Jacques Maritain Center : A History of Western Philosophy Vol. II / by Ralph McInerny

The Thirteenth Century

Chapter VI

Saint Thomas Aquinas

A. The Man and His Work

Almost twenty years ago a professor of philosophy remarked that there are more Thomists in the world than any other kind of philosopher, a remark that lost its surprise when one reflected that it was prompted by identifying every Catholic philosopher -- if not every Catholic -- as a Thomist. Things have changed in the meantime, for better or worse, but the remark retains some interest if only because it reveals how Thomas Aquinas has sometimes been swallowed by Thomism, that in his case we seem to be dealing less with an individual thinker than with an institution. In a broken rhythm but with general constancy since his death, men have come forward as intermediaries between Thomas and his reader. Commentaries on Aquinas, monographs devoted to particular points of his teaching, a bewildering barrage of journal articles, popularizations of his doctrine, even popularizations of the popularizations -- all this has sometimes had the effect of putting Thomas himself further and further away from the possibility of direct contact. Dominicans, members of Thomas' own order, have always been in the vanguard of these efforts to explicate, expand, and apply the teachings of Aquinas, but they have always been joined by other religious, by secular priests, and, more recently, by laymen, Catholic and non-Catholic.

The remarkable attention that has been paid the thought of Aquinas, while it relates to the essential quality of his work, cannot be understood on that basis alone. The favor shown Thomas by the Catholic Church over the centuries, the unique deference paid him in the Leonine revival at the end of the nineteenth century, added the weight of the ordinary magisterium of the Church to the attraction of the intrinsic qualities of Thomas' teaching and to his previous historical impact to insure for Aquinas an attention to his writings on the part of Catholics which goes far beyond that owed and paid to other important thinkers. This antecedent deference to the thought of Thomas has had disadvantages as well as advantages, and we are currently in a time when the mood of deference to Aquinas seems almost wholly absent from some Catholic philosophers. Just as earlier there were a few who equated repetition of what Thomas had written (a repetition that seemed most comfortable when it was of the original Latin) with understanding and philosophical argument, so now a few seem to take hostility to Aquinas as a sure sign of philosophical seriousness.

One childish attitude is scarcely preferable to another; the importance of Aquinas cannot be decided by hoisting a moist finger to catch the winds of current fashion. Our task here must be to get through the Thomistic tradition -- so much of which, taken in moderation, is undoubtedly an aid -- to the teachings of Thomas himself. When we do this, when we catch something of the flavor and style of his procedure and make soundings in the vast expanse of his teachings, we begin to see why he has been singled out for the attention he has received, why that vast tradition of scholarship and commentary arose, why he is one of a handful of truly major and perennial thinkers. Only then can we hope to speak intelligently of the role Thomas may play today -- and that he has a contemporary role to play is the continuing and insistent conviction of the teaching Church. But, of course, it will not be our task here to enter into any lengthy discussion of the timeliness of Thomas.

Thomas was born in 1225 in Roccasecca near Naples, and Aquinas is the family name taken from Aquino, where the feudal family into which Thomas was born ruled. Thomas' early education was at the Benedictine monastery of Monte Cassino. From 1239 to 1243 he studied the arts at the University of Naples, which had been founded by Emperor Frederick II in 1224. When Thomas entered the Order of Preachers in 1244, his decision met with resistance from his family; taken into custody by his brothers, he was held prisoner for several months, but they set him free in 1245. His first years as a Dominican are obscured for us, but we know that Thomas studied under Albert the Great at Cologne from 1248 to 1252. In the latter year he was sent to Paris, where he was a student of theology until 1257. He was a bachelor of Scripture from 1252 to 1253 and a bachelor of the Sentences from 1253 to 1256 in the Dominican convent in Paris. At the end of this period he was admitted as a master of theology and granted a license to teach on the faculty of theology of the University of Paris. His inaugural lecture was delivered in the summer of 1256.

It must be pointed out that these years of study at Paris were far from serene, for it was just at this time that the efforts of the secular clergy to keep the religious, particularly the mendicant friars, from faculty positions reached a peak of what can only be called frenzy. Thomas and Bonaventure were granted their degrees at the same time, but their admission to chairs on the faculty of theology was delayed. In October of 1256 Pope Alexander intervened to demand that they be received into the academic community. This demand was not complied with until August, 1257, by which time Bonaventure had been elected master general of the Franciscans. But for Thomas this marked the start of a professorial career which, one way or the other, defined his life until be died.

From 1256 to 1259 Thomas held one of the Dominican chairs of theology at the University of Paris. During this period he wrote his Commentary on the Sentences, or rather completed his comments on the work of Peter Lombard begun in 1253. To this period also belong his commentary on the Gospel of St. Matthew, the Disputed Questions on Truth, the expositions of the De trinitate and De hebdomadibus of Boethius, the opuscula On Being and Essence and On the Principles of Nature, and several quodlibetal questions. These few years represent the first stage of Thomas' career as a teacher and are called the first Parisian period.

The first Italian period begins perhaps in 1260 and extends to 1268. During this period Thomas taught first at Orvieto, where Pope Urban IV was in residence; from 1265 to 1267 he taught in Rome, at the convent of St. Sabine, and then perhaps at Viterbo, where the papal court had gone. During the first Italian period Thomas wrote the Summa contra gentiles as well as the first part of the Summa theologiae, the masterpiece which was still to be incomplete at the time of his death. He also wrote at this time the Disputed Questions On the Power of God and On Spiritual Creatures and commented on Pseudo-Dionysius' On the Divine Names. The commentaries on Isaiah and Jeremiah seem also to belong to this period. Of great importance for our purposes are commentaries on works of Aristotle, some of which, notably those on the Metaphysics and On the Soul, were begun during this period.

The second Parisian period took place between 1269 and 1272, when, on the orders of his superiors, Thomas reclaimed his chair on the faculty of theology at the University of Paris. In many ways this could be called the Aristotelian period of Thomas' career since during it he completed his commentaries on the Metaphysics and On the Soul and commented as well on the Physics, Nicomachean Ethics, Meteorology, On Interpretation, and the Posterior Analytics. At the same time he commented on the Liber de causis (pointing out that it amounted to a selection from Proclus' Elements of Theology). He also commented on Job, St. John's Gospel, and the Epistles of St. Paul. He continued working on the Summa theologiae during this period and engaged in many Disputed Questions, those On the Soul, On Evil, On the Virtues, and On the Union of the Word, as well as in many quodlibetal questions. It is to this period that the opusculum On the Unity of the Intellect against the Parisian Averroists belongs.

The second Italian period begins in 1272 and ends with the death of Aquinas in 1274. Thomas taught at the University of Naples, where he was sent in 1272 to found a Dominican House of Studies. Besides organizing the curriculum and teaching, Thomas wrote more commentaries on Aristotle, those On the Heavens, On Generation and Corruption, and on the Politics. Moreover, he worked on part three of the Summa theologiae. In 1274, on orders of the pope, Thomas set out for the ecumenical council to be held at Lyons. He never made it. Falling ill on the way, he was taken into the Cistercian abbey at Fossanova, located between Naples and Rome. It was there, when he was not yet fifty, that he died on March 7, 1274.

To summarize a life in this way gives us everything but the man who lived it, and of the man Thomas it must be remembered that he was priest and Dominican, teacher and mystic, scholar and saint. In Thomas we find a blend of the natural and supernatural virtues, the moral and intellectual virtues, and truly, insofar as man can say of man, Thomas exhibited in his own life the ideal of Christian perfection of which he wrote with authority and in a style that is almost never unctuous. There is a story that as a child he asked. "What is God?" lie followed the trail of that question throughout his life, not as the statement of a curious intellectual puzzle, but in quest of the ultimate meaning of life and of the universe. With respect to that controlling question of his life he was intent to run out the string of reason as far as it could go, and by doing so he came to hold that in the end the most we can do is know what God is not; we cannot know what or who he is with clarity in this life. This final position is not a sign of resignation or lethargy; it represents a learned ignorance which refers not simply to the limits of pure reason but also to the darkness and obscurity of the spiritual life. Intellectual and saint, Thomas speaks audibly both to the sophisticated academic and to the lyric mystic. St. John of the Cross professed to see in the treatise on the contemplative life in the Summa theologiae the map, insofar as it can be mapped, of the profundities of the spiritual life. Only the traveler who has returned can make us maps, and Thomas' credentials, unsettling for a certain view of the intellectual life, are incorrigibly dual: his holiness and his austere arguments.

It is not Thomas the saint who is our interest here, but Thomas the thinker, and however inseparable these were in his person, they can be considered apart. The writings of Aquinas which have come down to us are intimidating in their bulk and number; editions of his complete works fill shelves. Our sketch has indicated that they fall into classes. The first great division of his writings could be between those which comment on, explicate, or expose the writings of others on the one hand and independent works on the other. Among the latter we might include those which grew out of academic debates, the Disputed Questions and the Quodlibetal Questions, but more particularly various opuscula and, of course, the two great summaries of Christian theology, the Summa contra gentiles and the Summa theologiae.

Another way of grouping his writings, one more important for our purposes, would be into philosophical writings and theological writings. The former, of course, are what seem to interest us most, but what would they be? Such opuscula as On Being and Essence, On the Principles of Nature, and On the Unity of the Intellect certainly -- these are, on Thomas' own criteria, philosophical works, and, while dependent on his predecessors, they are original in their conception and development. Further, there is the great mass of his commentaries on Aristotle. There has been a dispute among students of Thomas during the present century concerning the status of those commentaries, a dispute which often swings around varying ideas of what Thomas was doing when he commented on Aristotle. Some have simply used the commentaries (despite the deplorable condition of the text of crucial ones like that on the Metaphysics) as unqualified repositories of the teaching of Thomas; others have suggested that in his Aristotelian commentaries Thomas is trying to make as clear as he can (and some would say he succeeds to a fault) what Aristotle is saying, without giving his own personal views on the matters in question.

One cannot, of course, in a few lines hope to settle a dispute in which men of acumen and sincerity have disagreed deeply, but some working conceptions for our present purposes seem both possible of formulation and necessary to our task. It seems unreasonable to ask that we ascertain the motives of Thomas the commentator, which could in no way be verified in the evidence we have. We must look at the commentaries, consequently, and see what we find there. We find, as some have insisted, a Thomas who takes great pains to discover precisely what Aristotle is teaching, what his questions are, what the order and development of the text are, and what is the structure of his arguments. Say then that we find Thomas the commentator showing us in great detail that such and such is the problem, so-and-so is the solution, and these are the reasons for accepting the solution. Are we then to ask whether he agrees or disagrees? This suggestion seems to me to be an invitation to distraction. Our attention must be on the question, solution, and arguments; the point is, Do we agree or disagree? If the discourse as Thomas presents it is cogent, to ask if he finds it so is irrelevant. Why should we doubt that he does? What I am suggesting, with respect to those who would downgrade the commentaries, is simply that a cogent argument, a reasoned position, in a commentary of Aquinas must quite naturally be assumed to be the one with which Thomas agrees.

Now this seems a terribly simple dissolution of a long-standing problem when we had said earlier that it would be difficult and indeed inappropriate to try to settle the matter in a few lines. I want now to develop the solution suggested in such a way that both sides in the dispute are given their due. In commenting on Aristotle, Thomas often takes into account other efforts to explicate the text; when he rejects those efforts, as he often does, it is because they make nonsense of Aristotle or negate the order and development of his thought. Now this sort of thing, which is so far from being rare that it is almost the mark of Thomas' Aristotelian commentaries, suggests that Thomas was deeply sympathetic with the philosophy of Aristotle, that he held Aristotle in an esteem that is quite unique in his relations to previous thinkers, and that this explains both the volume of his commentaries on Aristotle and the fact that he urged his Dominican friend, William of Moerbeke, to provide him with more accurate Latin translations of Aristotle. In short, we can employ Thomas' commentaries on Aristotle with the assurance that in them Thomas is striving for an accurate reading of Aristotle and he is doing so because, by and large, he agrees with the results of such a reading.

Having stated the matter in this way, we must hasten to add that no one doubts for a minute the impact of Aristotle on Aquinas. Indeed, save for infrequent exaggerated statements, no one would doubt for a minute what has been said about our proper response to cogent arguments in commentaries which are clearly regarded to be cogent by Thomas when he formulates them. That is not the point, we would be told; of course Aquinas agrees with Aristotle as far as he goes, but Aquinas often goes far beyond a text of Aristotle in commenting on it. One sees how the dispute now alters in character. At first it seemed to be a disagreement between those who insisted that there was only Aristotelianism in Thomas' commentaries and those who would find Thomism in those commentaries. Now it is those in the first group who insist that the commentaries are Thomistic and beyond mere Aristotelianism. This apparent switch points, however, to a most important truth.

No one could possibly doubt that Thomas is an Aristotelian; what those who object to an almost exclusive reliance on the Aristotelian commentaries have in mind is the fact that we cannot equate Aristotelianism and Thomism. This means at least the following: that there were other sources of the philosophizing of Thomas than the texts of Aristotle. Some insist on the influence of Christian faith, an influence which led him to philosophical positions, philosophically arrived at, which, if not incompatible with Aristotelianism, nevertheless represent a deepened version, perhaps even a transformation, of it. Surely this is not a priori an implausible suggestion. Others will call our attention to philosophical influences other than Aristotle which leave their mark on Thomas' teaching. Consider for example Aristotle's opposition to Plato. Does Aquinas too reject Plato? It would seem so, on the basis of the commentaries, but a number of recent works -- notably those of Fabro, Geiger, and Henle -- have pointed out the influence of Platonism on Thomas. A crucial consideration here is that of participation, which Aristotle rejects as a useless metaphor but which permeates the doctrine of Aquinas.

Our simple solution of the dispute thus gives much to both sides. We seem to find here as we often find elsewhere that when intelligent men disagree, they may on a more profound level be in agreement. However, to agree that not every philosophical teaching of Aquinas is already in Aristotle or derived from Aristotle is not of course to agree about the nature of the more commodious entity, Thomistic philosophy. One can accept, one must accept, the reminder that there is much Platonism in Aquinas, but that is not eo ipso to accept certain descriptions of the resultant Thomistic synthesis. It is the assumption of the present presentation that Aquinas was so fundamentally an Aristotelian that he accepted Platonic and Neoplatonic suggestions on an Aristotelian basis. That assumption is borne out by Thomas' procedure in commenting on the Liber de causis and on Pseudo-Dionysius.

When we distinguish between the philosophical and the theological writings of Aquinas, we are not suggesting that a history such as this one must restrict itself to the former. For reasons that will be made clear in the following section, formally theological works of Thomas contain much that is crucial for understanding his philosophy. A presentation of the philosophy of Aquinas must rely heavily on the Summa theologiae. Thomas' exposition of Boethius' De trinitate gives us one of the most lucid presentations of the nature of metaphysics and its relations to other philosophical sciences. For the reader who has come to this chapter from the preceding ones that fact will not he terribly surprising, of course, but let us now turn to what Aquinas has to say on one of our recurrent themes, the relation of faith and reason as well as on one of the allied themes, the relation of theology and philosophy.

B. Philosophy and Theology

The very first question Aquinas asks in his Summa theologiae is, Why do we need any doctrine or inquiry beyond philosophy? To pose such a question suggests, of course, that philosophy is or was a going concern and that later and by way of addition a new study was introduced, call it "theology." Thus, it is theology and not philosophy which must be justified. Thomas provides a number of reasons why theology seems superfluous. In the first place, if a man ought not try to know what is beyond his intellectual capacities and whatever is within those capacities falls to the concern of philosophy, philosophy is certainly sufficient for man. Further, teaching is concerned with something, with being, but no type of being seems excluded from philosophical consideration, certainly not divine being since Aristotle's name for metaphysics is theology.

Having made things look difficult indeed for the work he is undertaking, Thomas begins to move toward the contrary position by first quoting from St. Paul's Second Epistle to Timothy (3:16), where Scripture is said to be useful for teaching, arguing, correction, and so forth. It becomes clear that what Aquinas is thus opposing to philosophy, which includes a theology or teaching about God, is Scripture, in which God tells man of himself. "Divinely inspired Scripture does not belong with the philosophical disciplines, which are discovered by human reason. We see that the difference lies in the source of a doctrine: it is discovered by human reason or it is revealed by God. It is this opposition which Thomas stresses in the body of the article. "I reply that we must say that it was necessary for human salvation that there be a doctrine according to divine revelation in addition to the philosophical disciplines which are investigated by human reason. For, in the first place, man as man is meant for God, who is a goal surpassing reason's comprehension. . . . But the goal must be foreknown by men, who are to direct their intentions and actions to it. That is why it was necessary for man's salvation that things which exceed human reason be made known to him by divine revelation." (ST, I, 1, 1, c.) The assumption here is that God as man's goal is beyond the ken of man. And yet, had not Thomas conceded earlier that philosophy arrives at valid knowledge of God? He had, and this will of course lead to ambiguity in the use of the term "theology." There is the theology of the philosophers, and there is the theology contained in and based on Scripture.

Aquinas now says something quite important about the theology of the philosophers. "It was necessary that man be instructed by divine revelation even concerning those things which human reason can know about God. The truth concerning God as discovered by reason comes to only a few men after a protracted period of study and with the admixture of much error -- and yet on knowledge of such truth man's whole salvation depends, for that lies in God. Thus, it was necessary, if salvation was to come to men more fittingly and certainly, that men be instructed about divine things by divine revelation." (Ibid.) That last remark may seem confusing, as if Thomas were suggesting that through reason men could, though with difficulty and over a great span of time, arrive at truths concerning God which God has revealed to man. That suggestion is not wholly unintended, as we shall see, but precision is required.

For the moment Thomas is after another point. We remember that one of the arguments for the superfluousness of theology pointed out that philosophy studies God. Notice what Thomas now says of that. He first gives an example of how different sciences can prove the same truth, as the physicist and astronomer might prove that the earth is round by quite different reasons. If that is true, "nothing prevents that the same things be treated philosophically insofar as they are knowable in the light of natural reason and by another science insofar as they are known in the light of divine revelation. Thus, the theology which pertains to Sacred Scripture is generically different from the theology which is a part of philosophy." Without for the moment going into the fact that there are truths about God revealed in Scripture that would be inaccessible to human inquiry no matter how much time and effort were expended, Thomas concedes that philosophy arrives at certain truths about God which can also be gleaned from Scripture. With respect to such truths the argument for revelation bears on the difficulty of arriving at them philosophically, on the few men who have succeeded in doing so, and on the errors that mar their success. Yet even here Thomas draws our attention to the different ways in which the same truth may be held to be such, either on the basis of natural reason or on the basis of divine revelation.

This seems curious because two types of rational activity are apparently being compared, and then one is described as a rational activity, namely, doing philosophy. What are we to call the other, the acceptance of a truth as a truth because it is revealed by God? Thomas will call it "believing" the truth. For example, to hold, to affirm, to say that God is one, that there is but one God, because God says so, is to believe that truth. There is a mental attitude here vis-à-vis an object which finds form in a linguistic expression, "God is one." In speaking of faith as a condition or state of mind Thomas will want to contrast it with other mental attitudes, with other states of mind. Thus, he will compare "believing that A is B" with "knowing that A is B" and "intuiting that A is B" and "thinking that A is B." The symbols stand for subjects and predicates, of course, and perhaps we would normally say that we know or believe or think, not propositions, hut what propositions are about. Nonetheless, we can say that propositions or sentences express what we know or think or believe -- that, at any rate, is the way Thomas understands the matter, though in speaking of faith he will insist that we believe someone and something. What is the relation between the subject and predicate when we intuit that A is B? (I am using intuition here for Thomas' intellectus.) We intuit that A is B when the connection between the two is immediate, when no link other than that of subject and predicate is required to see that the proposition is true. A frequent example of such a truth in Aquinas is "the whole is greater than any of its parts." In order to see that this is true we need know only what a whole is and what a part is. (Notice that I did not say that we need know only what "whole" and "part" mean, since this could suggest that Thomas thought it is simply a matter of convention and that he shares the suppositions of many current discussions of "analyticity.") Once we know what a whole is and what a part is, the truth is immediately seen. To know that A is B, on the other hand, is to know a statement is true whose predicate and subject are connected or mediated by some third thing. That third thing is, of course, a middle term, and the connection of knowing with the conclusion of a demonstrative syllogism is apparent; so too, intuition bears on the principles of such syllogisms. To think that A is B, finally, is to assert a connection between subject and predicate on other than conclusive grounds. That is, intuition and knowledge are certain, whereas thinking, or opinion, is not. Enough has been said, perhaps, to introduce Thomas' notion of "believing that A is B."

Is believing that A is B like thinking that A is B? It is like it in that, as believed, no cogent reasons for the truth are known; believing is unlike opinion or thinking in that believing is unwavering and, in that sense, certain. Thus, faith is like knowledge and intuition in that it is certain and unwavering, but it is unlike both in that it does not involve the same sort of clarity. Further, what is known or intuited is, in principle, within the reach of any normal man if he pays attention and follows the argument. But faith, the acceptance of what God reveals, is not just the natural employment of a natural capacity. There is something surprising about faith, an intrusion into human affairs of something outside the normal course of events. That something more is, for Thomas, grace, the power of God, and it reaches the mind through the will. "To believe belongs to intellect insofar as it moved by the will to assent." (ST, IIaIIae, 2, 2, c.) What the mind assents to in faith is not seen, that is, to continue the earlier analysis, we do not see the connection between A and B. Faith involves an intellectual assent to what is believed, but intellectual assent is of course involved in intuiting, in knowing, even in opinion. "There is another way in which intellect assents to something, not because it is sufficiently moved by its proper object, but rather by a choice voluntarily inclining it to one side [of a contradiction] rather than to the other. If this is done with doubt or fear that the opposite might be true, there is opinion; if however it is done with certitude and without fear, it is faith." (ST, IIaIIae, 1, 4, c.) The proper object of intellect is what is seen; when the mind assents to something it does not see, whether mediately or immediately, it may do so because it is prompted by desire. Thomas suggests that such motivation is common to opinion and faith, but the great difference is that the believer is without doubt. Or is he?

Like Bonaventure, Thomas distinguished the certitude of adherence from the certitude of comprehension. Knowledge or intuition would possess both kinds of certitude; faith has only certitude of adherence and has it, Thomas argues, to a greater degree than do intuition or knowledge. It is because the assent of faith is prompted by the will, moved by grace, that while there is no wavering with respect to adherence to what God has revealed as true, there is a kind of movement, of mental discomfort, on the part of the believer with respect to believed truths. His assent, while mental, is not prompted by what is proper to intellectual assent as such. Thus, the believer reflects in some unease on the truths he has accepted on the authority of God, and this reflection or meditation may, when it is of a certain sort, give rise to what Thomas means by theology. Thomas makes this point by comparing believing with intuiting and knowing. Intuiting involves assent without prior cogitation, while the assent of the knower to what he knows follows on cogitation. "The knower has both cogitation and assent, but a cogitation causing assent and an assent which terminates cogitation." Belief or faith involves both cogitation and assent but, as it were, on an equal footing (quasi ex aequo). "For the assent is caused, not by cogitation, but by the will. In this way the intellect is not determined to one [side of a contradiction] as it is when it is led to its proper term, which is the vision of something intelligible; that is why its movement is not at rest, but cogitation and inquiry remain concerning those things which are believed, though the believer most firmly assents to them." (Q.D. de ver., 14, 1, c.) The mind of the believer is thus portrayed as restless since it has given its assent under the influence of will and not because of the evidence of what is assented to. The mind of the believer has been rendered captive, its assent prompted by something extrinsic to intellection as such. "Thence too it is that in the believer there can arise an impulse toward the contrary of what is most firmly held, something that does not happen in intuiting and knowing." (Ibid.) Having noted that certitude involves both firmness of adherence and evidence, Thomas can speak of the certitude of faith in various ways. With respect to firmness of adherence, "faith is more certain than any intuition or knowledge, because the First Truth, which causes the assent of faith, is a stronger cause than the light of reason which causes the assent of intuition or knowledge. It [certitude] also implies evidence concerning that to which assent is given; in this sense, faith has no certitude, though intuition and knowledge do." (Ibid., ad 7)

To know what Thomas meant by believing and knowing is to possess the prerequisites for understanding his distinction between theology and philosophy. Philosophy aims at knowledge which is discourse terminating in an assent prompted by the evidence of what the mind is attending to. The starting points of such discourse are truths knowable by everyone. This is why, when Thomas compares teaching and discovery, he will insist that teaching must imitate the route we would go if we were finding out for ourselves, at least in the sense that it must start from what may be presumed to be already known. What the teacher proposes must be shown to follow from what is already known by the pupil, and it is from that connection that it derives its force and commands assent -- not from the authority of the teacher. "If someone should propose to another something unconnected with self-evident principles or whose connection with such principles is not shown, he does not cause knowledge in him, but perhaps opinion or trust." (De ver., 11, 1, c.) The point is that each man has in principle the capacity for knowledge; there are certain truths that no one could fail to know. Such truths are the object of what we have been translating by intuition (intellectus). What is known is connected with such self-evident truths, which are premises or guidelines for reasoning. If another presents to us a statement that A is B, he must give us some grounds for assenting to the connection between the terms when this is not self-evident. What mediates between A and B in knowledge is not someone's say-so, but the evidence of what is being talked about. Thus, knowledge and, consequently, philosophy are portrayed as what any man in principle can come to have owing to his natural powers.

To believe through revelation that A is B is precisely to accept the connection on someone's say-so, namely, God's, and the motive force is the will drawn by the promise that such assent will lead to man's saving good. The will is a cause here under the influence of grace, a special intrusion of God's causality. To believe is not to be a theologian in Thomas' understanding of theology, although one cannot be a theologian unless he believes.

What does theology add to belief? Theology is the science of Sacred Scripture, that is, it is a discourse bearing on the truths revealed by God in Scripture. Revealed truth, the articles of faith, are the principles of theology, and in discussing the theologian's attitude toward them Thomas will invoke the practice within certain philosophical disciplines of accepting the principles and attempting to prove things other than the principles of the discipline. Metaphysics, unlike the other sciences, disputes with those who would deny its principles. Theology, like philosophical sciences in general, accepts its principles (the philosophical sciences accept theirs because of their evidence; theology accepts its principles on faith), and, like the metaphysician, the theologian disputes with those who would deny the principles of theology, that is, who would deny revealed truth. (ST, Ia, 1, 8, c.) The mark of theology, as Thomas conceives of it, is the use that it makes of what men naturally know, that is, of philosophy, in its discourse about what God has revealed. We remember Thomas saying that while faith involves the firmest assent, cogitation, a kind of discursive wavering with respect to what is assented to, remains. Theology may be regarded as addressing itself to this cogitation or, perhaps better, as being an instance of it insofar as the theologian tries to bring into relation with one another what is believed and what is known. Predictably, Thomas shows concern with the procedure or methodology of the theologian, asking whether it is licit to employ philosophical reasoning in theology. (De trin., q.2,a.3) Against this practice he arrays a barrage of quotations from Scripture and the Fathers, and fashions arguments against it by appealing to the methodological rules of the philosophers. Having done this, he shows that St. Paul himself used philosophical doctrines in his Epistles, cites the practice of the Fathers, and so on. With that dialectical background he develops his own position.

He begins by remarking that grace does not destroy nature but rather perfects it and that, thus, the light of faith, which is infused in us by grace, should not be thought to destroy the light of natural reason, which is also God-given. Of course, natural reason is inadequate with respect to the object of faith; nonetheless, it is impossible for the truths God has revealed to conflict with those known by the reason God has given us. Rather, naturally known truths are similitudes of a sort to what has been revealed. Thomas makes the point stronger. Natural truths are preambles to revealed truths. This is an extremely important teaching of his. We saw earlier that he holds that some things which in principle can be known by man have been revealed by God. Now, if some of the things God has revealed can be known in the strong sense of known, that is, by natural reason, this is a sign that other revealed truths, which are beyond our understanding, are also intelligible in themselves. There is thus a kind of bridge between natural knowledge and what can only be believed; it is this bridge that is meant by the phrase praeambula fidei.

Thomas distinguishes three ways in which philosophy can be used in theology. It can be used for demonstrating those things which are preambles to faith, that is, to prove by natural reason that God exists, that he is one, and other things concerning God and man which can be proved in philosophy and which faith implicitly or explicitly holds. Second, it can be used to make known what is believed by appealing to philosophical doctrines, as Augustine finds many similitudes to the Trinity in philosophical doctrines. Third, philosophy is useful to the theologian to resist what is said against the faith by showing the attacks to be false or at least inconclusive. The assumption here is that anything contrary to faith is false and that since it is false, it can be shown to be such on philosophical grounds; if it is only probable, that too can be manifested by philosophical reasoning.

There are, of course, dangers involved in the theologian's use of philosophy. Thomas mentions two of them. The theologian might employ philosophical teachings which are contrary to faith, which are corruptions of natural reasoning since they are false. Thomas mentions Origen as guilty of this. Second, he might try to submit revealed truth to natural reason as to an absolute measure. For example, he might want to believe only what can be proved by philosophical reasoning. The order should be the reverse, Thomas says. Philosophia sit ad metas fidei redigenda (philosophy should be submitted to the measure of faith). (De trin., q. 2, a. 3, c.)

Thomas sees no problem whatsoever with respect to the use of dialectic in reasoning about revealed truths. Except in the case of the praeambula fidei, truths which have been revealed but can be known by natural reason, there is no possibility of proving revealed truths. Insofar as dialectic is construed as simply a method of reasoning, the theologian can use it to prove, for example, that, given two revealed truths, a further truth can be derived from them. It is in this, as it happens, that he sees the possibility of an explication in time of the content of faith. (ST, IIaIIae,q.1,a.7) But beyond the employment of the method of philosophy in reasoning about the contents of faith the theologian, according to Thomas' conception of him, will often develop philosophical points in order to cast some poor light on the mysteries of faith. Thus, the notions of person, nature, relation, and so forth are clarified to a remarkable degree in the course of the theologian's deliberation on the mysteries of the Trinity and the Incarnation. There is a striking amount of such philosophical clarification in the Summa theologiae, as, for further example, in the treatise on man and in the moral parts.

Because of this, interpreters ask if Thomas is then to be thought of as doing philosophy or theology. It is not facetious to reply that he is doing both. His overall purpose in a theological work is of course theological, that is, to achieve such understanding as is possible concerning the objects of faith. But his very conception of how to do this indicates that much philosophy must be brought into play. With respect to philosophical arguments and clarifications in theological works of Aquinas it must be said that insofar as they are philosophical, their worth and acceptance does not depend upon the acceptance of faith. That is why Thomists, in the course of philosophical writing, will often refer to passages which occur in the theological writings of St. Thomas. When they do this, they are not asking their philosophical reader to accept the overriding assumptions of theology, that is, the truths revealed by God. The passages referred to are found in a theological context, but if they are philosophical, acceptance of them demands appeal only to principles knowable by every man on a natural basis. Thus, in presenting a sketch of the philosophy of Thomas, as we are attempting to do here, we can legitimately cite passages from theological works precisely because these theological works are filled with philosophical passages.

A caution must be made nonetheless. Often in a theological work of Aquinas we can read for pages without encountering significant appeals to truths accepted on faith. Nevertheless, any such section, being a section of a theological work, draws its order and plan from the work of which it is a part. The order and procedure of the Summa theologiae is not, in its main lines, philosophical but precisely theological. Reasons can be adduced from Thomas to show that the order of the Summa is not and could not be the order of philosophical reasoning. Let one reason suffice. The Summa takes up at the very outset the existence of God, but this is a question which philosophy can fruitfully ask only in its culminating part. In the case of Thomas, however, we encounter far less trouble than we do in the case of a theologian like Bonaventure in determining what is the philosophical whole into which the philosophical passages which occur in theological works fit. Thomas provides us with a highly developed notion of what the term "philosophy" covers and clues as to what part of philosophy a random consideration would belong. Let us turn now to the notion of the nature and parts of philosophy.

C. The Division of Philosophy

Thomas' conception of what philosophy is and of how it is divided is basically Aristotelian, but he strives to incorporate into this conception the other major traditions. Thus, he will on occasion make use of the Stoic division of philosophy, which was used by Augustine, into natural science, ethics and logic. "Because reason's consideration is perfected by habit, there are diverse sciences following on the diverse orders which reason properly considers. For it pertains to natural philosophy to consider the order of things which human reason considers but does not cause, insofar as metaphysics is included under natural philosophy. The order that reason introduces into its own act of consideration pertains to rational philosophy, which considers the order of the parts of discourse to one another and the order of principles to one another and to conclusions. The order of voluntary actions pertains to the consideration of moral philosophy." (In I Ethic., lect. 1, n. 2) Further, he will incorporate into his conception of philosophy the tradition of the liberal arts. This can be seen if we first consider his notion, developed from hints in Aristotle, of the proper order of learning the philosophical sciences. For the term "philosophy" covers a variety of disciplines.

When he comments on Aristotle's discussion of wisdom at the outset of the Metaphysics, he, like Aristotle, is impressed by the etymology of the term "philosophy": the love of or quest for wisdom. Wisdom is the knowledge of all things in their ultimate causes, and philosophy, accordingly, is seen as a drive toward knowledge of the highest and best reality, that is, knowledge of the divine. Any intellectual inquiry is philosophical to the degree that it is necessary for or useful to acquiring knowledge of God. Hence, the various philosophical disciplines are ranged with respect to the culminating consideration of philosophy, and this is part of what underlies Thomas' notion of the order of learning. "Thus it is that the chief intention of the philosophers was that they might come to knowledge of the first causes by means of everything they considered in reality, and thus they placed the science of first causes last and assigned the consideration of it to the final period of life. Beginning with logic, which treats the mode of sciences, they proceeded to mathematics, something which even the young can grasp; they then went on to natural philosophy, which, because of experience, requires time; fourth came moral philosophy, since youth are not good students of it. Finally they came to divine science, which considers the first causes of beings." (In librum de causis, proemium) The tradition of the liberal arts had divided the seven arts into two groups. The arts of the trivium (grammar, rhetoric, and dialectic) Thomas reduces in the above list to logic; the arts of the quadrivium (arithmetic, geometry, astronomy, and music) he reduces to mathematics, and thus he absorbs into his Aristotelian conception the arts preparatory to wisdom. (De trin., q. 5, a. 1, ad 3) He actually cites Hugh of St. Victor in this regard, but in doing so he alters the view of Hugh himself, since the wisdom Hugh had in mind as the goal of these arts as ways (viae) was not metaphysics in the Aristotelian sense.

In what way are the various disciplines which are ranged in the order of learning distinguished from one another? Thomas accepts from Aristotle a first division of philosophy into speculative and practical. "It must be said that the theoretical or speculative intellect is properly distinguished from the operative or practical in that the speculative has for its end the truth which it considers, the practical orders the truth considered to operation as to its end." (De trin., q. 5, a. 1) Thomas does not mean that we have two intellects; he is drawing attention to the two uses we make of our mind. (ST, Ia, q. 79, a. 11) Thomas introduces three criteria which must be taken into account when we speak of knowledge as speculative or practical, one of which, the end of the knowledge, has already been mentioned. The other two are the object and the method of knowing.

In the speculative use of our mind we have in view no end beyond the perfection of the act of knowing itself, and perfection is truth, to be in conformity with the way things are. When our thinking is aimed at the perfection of an activity other than thinking, say the perfection of choice, then it is called practical. We can see that these different uses of our mind can be dictated by the nature of its objects. Thomas will point out that there are some things that we cannot do or make, and thus our only cognitive attitude toward them is speculative. His examples are God and natural objects. Insofar as our purpose in knowing is the perfection of the act of knowing or some other activity, our method of knowing the object will differ. Thomas' point here can perhaps be captured by saying that the method of practical knowing is expressed in something resembling recipes. That is, if you want to build a house, first do this, then that and that, and, voila, there is your house. Speculative knowledge of an object does not reduce it to the steps whereby we might bring it into existence, but proceeds by a resolution into its defining principles. Much more could be said of all this, of course. We might point out that insofar as there are various criteria of speculative and practical knowledge, knowledge can be to a greater or lesser degree speculative or practical insofar as it saves one, two, or all of the criteria of the one kind of knowledge. This is a point to which we will return when we consider Thomas on moral philosophy.

Division of Speculative Philosophy. Thomas calls the objects of practical and speculative philosophy, respectively, the operable and the speculable. It is by considering the notes of the latter that he finds grounds for distinguishing various speculative sciences. There are two proper characteristics of the speculable object, Thomas argues, and these are drawn from the nature of the intellect and the demands of science, which is the quality of intellect as it bears on the speculable. The intellect, Thomas says, and we will look later at his reasons for this assertion, is an immaterial faculty; consequently, if anything is to be an object of intellect, it must be in some way immaterial. Science, knowledge in the strong sense, bears on what is necessary. To know that the sum of the internal angles of a plane triangle is equal to two right angles is to know what cannot be otherwise and is thus necessary. But what cannot be otherwise is immobile or unchangeable. All this is shorthand for matters which are not self-evident and are not taken to be such by Thomas. Nevertheless, on these assumptions he is able to conclude that immateriality and unchangeability are essential characteristics of the speculable, the object of speculative philosophy. "Therefore, it is according to the order of removal from matter and motion that the speculative sciences are distinguished." (De trin., q. 5, a. 1) This removal from matter and motion is first indiscriminately described by Thomas as a separation or abstraction, terms which later acquire meanings owing to which they are opposed.

If separation or abstraction from matter and motion is essential to the objects of speculative thinking, insofar as there are different types or degrees of such abstraction we will have formal differences among speculative sciences, since the difference will be read in terms of what is essential to the speculable as such. We will seek this difference in definitions, for reasons which become clearer when we consider Thomas' doctrine on the paradigm of scientific reasoning. Now, we do find different modes of defining with respect to removal from matter and motion. "There are some speculables which need matter in order to be, since they cannot exist except in matter, but these are further distinguished, since some depend on matter both to be and to be understood, like those in whose definitions sensible matter is put and which are thus unintelligible without sensible matter; for example, it is necessary to put flesh and bones in the definition of man. Physics, or natural science, is concerned with things of this kind. Others indeed depend on matter in order to be but not to be understood since sensible matter is not put in their definitions, for instance, line and number; mathematics is concerned with these. Further, there are speculables which do not depend on matter in order to be because they can be without matter either because they never are in matter, like God and angels, or in some cases are in matter and in others not, like substance, quality, being, potency, act, one and many, and the like, with all of which theology is concerned, that is, divine scienue, the chief object of which is God, a science also called metaphysics, that is, beyond physics, because for us, who must proceed from sensible things to that which is not, it is studied after physics." (De trin., q. 5, a. 1)

This is a very difficult doctrine, but perhaps something can be seen of the precision with which Thomas handles what might seem to be acceptable merely as a de facto division of intellectual labor into natural science, mathematics, and metaphysics. If he is to admit that there are different speculative sciences, he must seek the difference in what is essential to the object of speculative philosophy. By citing the essential characters of the speculable, Thomas is able to give a statement of Aristotle's division of speculative philosophy which is a good deal clearer than that of Aristotle.

Division of Practical Philosophy. The principle of the division of moral philosophy is drawn from the fact that practical thinking is concerned with the perfection of an activity other than thinking. Thomas, in commenting on the discussion of prudence in book six of Aristotle's Nicomachean Ethics, makes a distinction, called for by the text, between political and ethical prudence (practical wisdom). (In VI Ethic., lect. 7, n. 1196) These are substantially, that is, generically, the same, he argues, in that both involve right reason with respect to what ought to be done concerning human goods and evils, but they differ specifically. What we are calling ethical prudence is the concern of a man with his own good, whereas political prudence is a concern with the goods and evils of the whole civic community. Besides these two kinds of prudence there is economic prudence, which is concerned with the good of more than one and of less than the whole civic community, that is, the good of the family. These three are intellectual virtues and, as such, presuppose a right disposition of the will, but the distinction enables Thomas to proceed to distinctions of practical, or moral, philosophy. "It should be noticed that, as has been pointed out, prudence is not of reason alone, but depends on appetite. What we have been speaking of here are species of prudence insofar as they do not consist of knowledge alone, but depend on an appetitive condition. Insofar as they are in reason alone, they are called practical sciences, namely, ethics, economics, and politics." (Ibid., n. 1200)

To make this less obscure, let us recall what was said earlier about the various criteria of speculative and practical thinking. The first and minimal criterion of practical thinking is that the mind be concerned with something we can do or make. Moral philosophy for Thomas is concerned with man's rational choices. The task of moral philosophy, he writes, "is to consider human operations insofar as they are related to one another and to the end." (In I Ethic., lect. 1, n. 2) But a human action may be considered in various ways; it may be approached in much the same way as we think of objects whose existence is not dependent on any choice of ours. Thomas' distinction of types of prudence or practical wisdom is an example; he is dividing a genus into species. A more practical method would be to know how to perform, what must be done, in order to achieve a given practical goal. That is why "normative discourse" rather than distinctions, definitions, and so forth, would be thought of as particularly ethical. Thomas would say that to know an operable thing as to how it can be done is a knowledge more practical than that whereby we know an operable in the same way we know speculable objects. What happens to knowledge when the third criterion of practical knowing is saved, namely, intention? Completely practical knowing, for Thomas, is exemplified in acting, and since actions are singular, we must say that completely practical knowledge is singular. Therefore, what Thomas in commenting on the Ethics gave as the distinction between types of prudence and types of practical philosophy, namely, presence or absence of a certain appetitive condition, can now be clarified by saying that practical science is at a level of generality in a way in which prudence is not. Practical sciences (the division of moral philosophy) are general judgments of man's good and of the way it can be attained, and insofar as the good is the good of the individual, of the family, or of the whole civic community, the judgments differ accordingly and so too do the sciences.

Like Aristotle, who is his mentor here, Thomas grants philosophy a charter so broad that it includes every natural intellectual pursuit insofar as it is necessary for or conducive to the attainment of knowledge of God. The point of moral philosophy is not cognitive perfection as such, but virtuous action. But moral virtue is conceived by Thomas as dispositional with respect to our seeking the perfection of our mind as such. That is why moral philosophy is philosophical.

Let us go on to give brief sketches of basic areas of Thomas' philosophical doctrine.

D. Logic

What did Thomas conceive logic to be, and with what is it concerned? In the preceding section we quoted a passage in which Thomas made use of the division of philosophy into natural science, logic, and ethics. That same passage contains a very brief statement of the object of logic, namely, the order introduced into reason's very act of considering objects. We must now try to understand that remark, and we begin by citing another. "As Aristotle says at the beginning of the Metaphysics, the human race lives by art and reason, a remark in which the Philosopher seems to hit on something proper to man whereby he differs from the other animals. For the other animals seem to be led by instinct in their actions, whereas man is directed in his by the judgment of reason. Thus it is that the various arts serve to perfect human acts so that they take place easily and in an orderly fashion, for art seems to be nothing else than a determinate ordination of reason whereby human acts arrive at their appropriate ends by determined means. But reason can not only direct the acts of inferior parts; it is even directive of its own act. It is proper to the intellective part that it reflects on itself, for intellect understands itself, and similarly reason can reason about its own activity. Now, if, as a result of reasoning about manual activity, the building art is discovered, an art which enables man to perform acts of a certain kind easily and in an orderly fashion, by the same token an art seems necessary which is directive of the act of reason itself, through which art man might proceed in reasoning in an orderly fashion, easily and without error. This art is logic, or rational science." (In I Post. Analytic., proemium, n. 1)

The assumptions of this passage are several. First, reasoning is taken to have a goal, namely, truth; and, second, it is not so determined to that goal that the possibility of error is excluded. Reflection on the reasoning process will permit us to devise an art which will direct reasoning more surely to its goal. Well, we might say, if an art, then artifacts. What are the products of this art? Notice that there is a necessary duality implied by the notion of reason reflecting on its own act, reasoning on reasoning -- for in the first, or basic, type of reasoning we are presumably concerned with known objects other than reasoning itself. The things we first understand, what reasoning first intends, leads to talk of prima intellecta or primae intentiones. On the assumption that unless we are thinking of or reasoning about something there would be no activity to reflect on, what is involved in reflection comes to be called secunda intellecta or secundae intentiones.

In the passage from the Commentary on the Ethics Thomas spoke of this reflective reasoning as constituting an order. What is the logical order? Thus far we have a few clues. Logic is not reasoning about just anything, but reflective reason, reasoning about reasoning. This makes logic sound like an introspective psychology, and logic is not psychology for Thomas. For one thing, Thomas will make use of a distinction between real being (ens reale) and rational being (ens rationis), and psychological activities are instances of real being.

Perhaps the best way to achieve clarity here is to compare a list of sentences: (1) man is rational, (2) man is a species, (3) man is white. The subject of each sentence is the same, so clearly it is the predicates that interest us. Consider first the difference between the predicate of (1) and the predicate of (3). In a word, the predicate of (3) is said to be accidental, because it is not predicated of everything of which man is predicated, and even when it can be truly predicated of a man, it does not tell us what he is, or something of what he is, as does rational. Let us call rational an essential predicate -- it expresses the very nature of that of which it is predicated. To get at the difference between (1) and (2), consider the following discourse. Man is rational, and Socrates is a man. We feel no hesitation in formulating a further sentence: Socrates is rational. But if we should say, "Man is a species and Socrates is a man," we would hesitate to go on to say, "Socrates is a species." "Man is a species," we would want to say, is a lot more like "Man is a noun" than it is like "Man is rational." Take "Man is a noun. This tells us something about man, not in terms of what it might stand for in the world, but in terms of grammatical relations. What are we saying of man when we say, "Man is a noun" or "Man is a species"? Well, again, we are not attributing something to human nature, mentioning it in terms of an intrinsic component, as when we say that man is rational. Are we then predicating something accidental of it? Surely it is accidental to human nature that the linguistic expression for it is in grammar a noun. But if it is accidental to what "man" signifies that "man" should be a noun, just as it is accidental to human nature that the English word "man" is a three-letter word and its Latin equivalent a fourletter word, such accidental predicates are not like the predicate of (3) above. "Man is white" involves an accidental predicate, but the sentence is true because it happens that in the real, extramental world some things that are men are white. That "man is a noun depends on the intrusion of man into the world and results from a characteristic activity of his, the formation of grammars. With this as background, let us approach (2) above. If "noun" is a grammatical term, "species" is a logical term. Other examples of logical terms are "predicate," "syllogism," "proposition," "middle term," and so forth. But let us stay with "species." What does "man is a species" tell us; what does "species" mean? For Thomas "species," like other logical words, signifies a relation a nature takes on as known by us. Something is a species if it is predicable of many numerically distinct things, as "man" is predicable of Socrates and Plato and so forth. We are back at the problem of universals, since species is a type of universal, one of Porphyry's predicables. To be predicable pertains to a nature like human nature accidentally; it is not an accident of a nature because of its presence in individuals as is the case with whiteness and man.

The logical order, as Thomas sees it, can now be defined as the relations which obtain among things as they are known and named by us. Furthermore, the logical order is intimately tied to our abstractive way of knowing. Like Aristotle before him, Thomas is struck by the fragmentation reality undergoes in our knowing process, a fragmentation which calls for the kind of ordering and binding together provided by logical relations. For example, we might first know of something simply that it is something-there, a being, then that it is a substance, then that it is living, then that it has senses, and finally that it is rational. If we stop there and collapse these steps, we would have the meaning of the term "man." But we can also label the preceding steps: "substance," "living substance," "animal"; and we might call them genera, as in the sentences "substance is a genus" or "animal is a genus." Now, what is expressed by "substance," what it means, is such that it can be predicated of objects in the world (the same would be true of "animal"), but to be a genus, in the sense of being predicable of many specifically different things, is true of the nature only as it exists in the mind. Furthermore, it is only in the mind that substance exists apart from further determinations like "living" and "nonliving." Thus, in this case certainly it is our abstractive mode of knowing, the fact that we move through progressively less vague "fixes" on things to determinate knowledge, that is productive of the "things" related by logical relations. This is something we must keep in mind when we consider the question of whether the categories (literally, predicates) of being are logical or real, but that is another consideration.

The objects of logic are the relations which accrue to things as they are known by us, relations which are accidental to the nature known. The divisions of logic, for Thomas, are precisely what he takes to be Aristotle's divisions. The bases for the division are the various acts of reason, since these acts are what logic is said to order and direct. Thomas speaks first of an understanding of incomplex things which expresses itself in definitions. Obviously, if something can be defined, it cannot be wholly incomplex or simple. Let us then start with rational discourse, with the syllogism. If C is predicated of everything of which B is predicated, then C is predicated of everything of which A is predicated. Such discourse can be seen as composed of such symbolically expressed propositions as "Every B is C" and "Every A is C." Apart from and prior to considering the relations among propositions in such discourse, we can consider the relations involved in affirming or denying one thing of another just as such. But the things which enter into affirmations and denials must first be known as to what they are, that is, must be defined. Thus, the parts of logic are, in a sense, the parts of rational discourse. "There are three acts of reason of which the first two belong to reason insofar as it is intellect [intellectusl. For one act of intellect is the understanding of indivisible or incomplex things, insofar as it conceives what a thing is. To this operation of reason is ordered the doctrine Aristotle treats in the Categories. The second operation of intellect is composition or division, where the true or false first obtains. The doctrine Aristotle treats in On Interpretation serves this act of reason. The third act of reason is one proper to reason as such, namely, discourse from one thing to another so that from what is known knowledge is gained of what was unknown. The rest of the books of logic serve this act." (In I Post. Analytic., proemium, n. 4)

The act of reasoning is sometimes necessary, sometimes probable, and sometimes fallacious. The first, necessary reasoning, is scientific and is called by Thomas judicative logic "because judgment is had with the certitude of science." Judgment is said to have its certitude owing to a resolution or analysis into principles, so this part of logic is also called analysis or analytics. "The certitude of judgment, however, which comes from resolution is either from the form of the syllogism alone, and the Prior Analytics is ordered to this, or is also from the matter, because it involves propositions which are selfevident and necessary, and with this the Posterior Analytics is concerned, which deals with the demonstrative syllogism." (Ibid.) The second part of the logic of reasoning is called inventive logic or the logic of discovery. Now what is discovered must be judged, and the term may be science if the judgment is with certitude; if not, if the resultant knowledge is only probable, then it is the concern of what Aristotle calls dialectics and is dealt with in the Topics. One can see Thomas the commentator at work here, incidentally; he is surely trying to say something accurate about the contents of and relations between the works of Aristotle's Organon, but what comes first, and in his own name, are the statements about the subject matter. He goes on to link the Rhetoric and Sophistical Refutations, and even the Poetics, with the logic of discourse. One is tempted to associate this treatment of the Poetics with Thomas' reduction of the arts of the trivium to logic. The only completed commentary on a logical work of Aristotle is that on the Posterior Analytics, but Thomas began one on On Interpretation and carried it forward a good distance. Among his collected writings are a number of opuscula whose authenticity has been questioned, one on modal propositions, another on demonstration, one on the square of opposition, and another on fallacies. In the commentaries on Aristotle's logical works Thomas exhibits his usual acuity, and it is easy to wish he had commented on the whole Organon. But with logic, as with many subjects, we find illuminating remarks scattered throughout Thomas' works. A notable example is his teaching, which must be pieced together from many sources, on systematic ambiguity, or analogy.

Logic has, of course, come a long way since Thomas, come so far indeed that it is questionable whether the term logic must not be taken to be ambiguous as applied to what Thomas meant by it and to what logicians do today. Historians of logic, writing from the standpoint of twentieth-century logic, are seldom detained by Thomas' contributions to the subject, but quite often such historians are indifferent to what logic may have meant in earlier times and seek only foreshadows of what logic has come to mean today. This procedure, while it achieves results of value, is finally perhaps as historically suspect as a "Thomistic" critique of the Principia Mathematica would be. To see how contemporary thought has "gone wrong" from a thirteenth-century vantage point is as dull as seeing how medieval logic "fell short" from a twentieth-century vantage point. We have yet to see a comparison of "logics" which does justice to historical periods taken on their own terms. When such a history of logic is written, Thomas may well occupy a prominent place in it, not as an innovator, but as a lucid exponent of the view that logic is not concerned with the most abstract language, with symbols or variables whose values are the things of this world (or nothing), but with rational relations accruing to things as the result of our knowing them. That is, that logic is incorrigibly human, all too human, and that its purpose is the quite human one of assuring the correctness of discursive reasoning about objects other than logical entities.

E. Natural Philosophy

One of the most shocking things about the Thomist in the eyes of his colleagues must surely be the attention he pays to what Thomas had to say about our knowledge of the natural world. The source of the shock is not simply that Thomas lived in the thirteenth century, which is prehistoric enough as far as natural science goes, but more basically still that in natural philosophy Thomas is spiritually in the same place as Aristotle in the fourth century B.C. It would be quite easy to list tenets of Thomas in natural science which could seem quaint at best and weird at worst; even if we should think that such is the stuff of which history is made, at least the history of science, we might question the advisability of devoting time to it in a volume as restricted in length as this one. Much better, it might be thought, to pass over in generous silence this part of the philosophy of Thomas and push on into his metaphysics. But that is precisely the problem. For Thomas there is little point in pushing on into metaphysics unless we have gained some purchase on the physical; in a word, if his physics is totally undermined, his metaphysics is a fortiori undermined. This is why Thomists pay so much attention to such writings of Thomas as his commentaries on Aristotle's natural works and his own On the Principles of Nature. It is true that these writings are so different from what we nowadays call natural science that the tendency often is to call the doctrines contained in them metaphysical. Nevertheless, for Thomas they amount to natural science, and that is how we shall consider them. To put what we shall try to say in a proper perspective, consider the following question. Is knowledge of the natural world possible, knowledge which in a significant sense is scientific, which does not employ the methodology of current natural science? If such knowledge is possible, there is no reason why it could not have been had prior to the development of scientific methodology in more recent senses of the phrase; it could have been had in the thirteenth century, even in the fourth century B.C., and need not be thought of as a competitor with or substitute for what we now call natural science.

In this section we shall consider three topics, the first of which is Thomas' statement of the hylomorphic composition of natural, or physical, things. The next two topics bear on what Thomas takes to be the presuppositions of metaphysics, the proof of the separability or immortality of the human soul, and the proof for the existence of an unmoved mover. These proofs are the reasoned ground for the conviction that "physical being" and "real being" are not synonymous and that, consequently, the science of being as being is distinct from natural science.

Hylomorphism. In On the Principles of Nature Thomas sets down this doctrine in a swift, staccato way. Some things can be, some things already are; the first are said to be in potency, the second in act. There are two kinds of actual being, however, substantial and accidental; it is one thing to be a man and another thing for a man to be white, and something can be in potency to either kind of being; what is in potency can in either case be called matter, though that which is in potency to substantial being might be called the matter out of which (ex qua) something comes actually to be, whereas that which is in potency to accidental being might be called the matter in which (in qua) something comes to be. "Again, properly speaking, that which is in potency to substantial being is called prime matter, but that which is in potency to accidental being is called the subject, for the subject gives being or existence to the accident, since the accident has no being save in its subject; hence, it is said that accidents are in a subject, but substantial form is not said to be in a subject. Matter differs from the subject in this: that the subject is not something which exists because something advenes to it; rather it is autonomously (per se) and has complete being; for example, a man does not come to be (a man) thanks to whiteness. Matter, on the other hand, has being from that which advenes to it, since of itself it is incomplete, indeed has no being. . . . Hence, absolutely speaking, form gives being to matter, but the accident does not give being to the subject, but the subject to the accident (De princ. nat., chap. 1) Having introduced two kinds of composition, that of prime matter and substantial form and that of subject and accident, Thomas goes on to speak of the coming into being of these two kinds of composites as, respectively, substantial and accidental becoming.

Accidental becoming is exemplified by a man's becoming pale. The acquisition of this quality does not make a man be a man, but a pale man. Man is the subject of the change, and prior to the acquisition must have been capable of possessing the quality, in potency to it, though at the time not in possession of it and thus deprived of it. A man moves from not being pale to being pale. Despite the restrictiveness of his earlier definitions, Thomas allows that the subject can be called matter. "Therefore, there are three principles of nature, namely, matter, form, and privation, of which one, form, is that for the sake of which the generation takes place. The other two are that from which the generation takes place. Hence, matter and privation are the same in subject but are different in conception (ratione), for bronze and unshaped are the same thing before the advent of form, but from one point of view the thing is called bronze and from another unshaped. Hence privation is said to be a principle not per se but per accidens, because it resides in the matter (Ibid., chap. 2)

Substantial becoming, the coming to be, not of pale man, but of man, is similarly analyzed. If "man" names something one and autonomous, something substantial, the form that makes a man to be is not like the quality which presupposes a substantial subject. Humanity is not something that advenes to an already existing thing to make an accidental compound like white man. The subject of a substantial change is called prime matter precisely to distinguish it from the subject of an accidental change; prime matter is not a substance as is the subject of an accidental change. For much the same reason the form involved in the substantial change is called substantial form: the being it constitutes by advening to prime matter is a substance. Whatever comes to be as the result of a change is a compound of matter and form. This is what the term "hylomorphism" conveys, of course, fashioned as it is from the Greek terms for matter and form. Matter and form are thus two ways of accounting for a physical thing, two causes, or principles, of its being. Besides these intrinsic causes there must be an efficient, or moving, cause which effects the composition of matter and form. Like Aristotle, Thomas also speaks of a final cause, that for the sake of which the change takes place and which in that sense terminates it. The form or the product of the change is the final cause of the change, but the final cause of the change is not of course the final cause or goal, that for the sake of which the product of the change exists. That is, a man may be the final cause of a substantial generation, but man's goal or final cause is not simply substantial existence.

The Unmoved Mover. We will present this proof in the statement Thomas gives it in his Summa contra gentiles, book one, chapter thirteen, a statement which is fuller than that found in the Summa theologiae and closer to the proof as it is developed by Aristotle in his Physics.

"Everything that is moved is moved by another." The fact of motion is evident to the senses, and the nature of motion demands that what is in motion is moved by another. But the mover is either itself moved or it is not. If the latter, then we have an unmoved mover (which can be taken to be a description of God); if the former, either what moves the mover is moved by another or it is not. Now either we must posit an infinite series of moved movers or we arrive at an unmoved mover. But an infinite series of moved movers is impossible, so there must be an unmoved mover.

As Thomas points out, there are two assumptions here that must be proved, and they are precisely the premises of the proof: "Every moved thing is moved by another" and "An infinite series of movers and things moved is impossible." He selects from Aristotle several proofs of the first premise.

First, if something moves itself, it must have within itself the principle of its motion, for otherwise it would manifestly be moved by another. Further, it must be what is first moved, not some part of it, as an animal being moved by its feet, for then it is moved not by itself but by its part, and, indeed, one part by another. And it is necessary that it be divisible and have parts, since whatever is moved is divisible, as is proved in the Physics, book six, chapter four. Given all this, the following argument can be devised. "That which is posited as moved by itself is itself first moved [primo motum], and thus the repose of one of its parts entails the repose of the whole. For if when one part comes to rest, another part should remain in motion, then the whole itself is not what is principally moved [primo motum], but its part which is moved while other parts are at rest. Nothing which comes to rest when another thing comes to rest is moved by itself, for whose repose follows on the repose of another must be such that its motion is a consequence of another's motion, and thus it is not moved by itself. Therefore, that which was posited as being moved by itself is not moved by itself. Therefore, it is necessary that whatever is moved is moved by another." The nub of the argument, according to Thomas, is this: "If something moves itself first and as such and not by reason of parts, it is necessary that its being moved is independent of anything else; however, for a divisible thing to be moved, as for it to exist, depends upon its parts and that is why it cannot move itself first and as such [primo et per se]."

Another proof of the first premise is this. "Nothing is simultaneously in act and in potency in the same respect. But whatever is in motion is, just as such, in potency, since motion is 'the act of that which is in potency just as such.' But whatever moves is as such in act, since nothing acts except insofar as it is in act. Therefore, nothing can be, with respect to the same motion, mover and moved. Thus, nothing moves itself."

Thomas offers several proofs in support of the second premise of the argument which concludes to the existence of a mover which is itself unmoved by another. That there cannot be an infinite series of subordinated moved movers is a good deal more difficult to prove, and the arguments are too technical and demand too much subsidiary commentary to go into here. In examining these arguments, as in examining those brought forward in support of the first premise, one is struck by the dependence on the Physics of Aristotle, and when one reflects that the proof of the unmoved mover comes at the end of the eight books of that work and depends on nearly everything that has come before, it is not surprising that Thomas, in giving a résumé of the argument, must presume so much. That presupposed doctrine is the source as well as the corollaries of the proof. If whatever is moved is moved by another and if this series cannot proceed to infinity, so that there must be a mover not itself moved, the nature of this unmoved mover can be approached by denying of it characteristics of things which are moved. Suffice it to say for now that matter is a component of what is moved and that thus the unmoved mover must be immaterial. The point is that in the course of doing natural science Aristotle and Thomas following him feel they must admit the existence of something immaterial. Thus, "being" is no longer synonymous with "material being," and the need for a science beyond the natural sciences is seen.

The Immortality of the Human Soul. There is another instance within natural science where one comes to see the existence of something immaterial, this time in biology. It should be said that considering natural science generically, we can say that its subject is mobile being. The predicable scope of such a phrase is, of course, great, and Thomas accepted Aristotle's view that on this level of generality it is possible to formulate proofs which would conclude to properties commensurately universal with the subject. That is, as a first step in natural science we can arrive at some scientific knowledge of what must pertain to any mobile thing, whatever differences among kinds of mobile being must later be taken into account. The Physics of Aristotle is precisely an attempt at a general science of nature, and its doctrine is thought to transcend the differences between living and nonliving natural things. One would not be content with such general knowledge of the natural world, of course, and in On the Soul Aristotle commences the study of living being. What distinguishes the living from the nonliving is precisely the former's possession of soul. What is meant by "soul"? The soul is that owing to which we live, move, sense, and understand. This definition, which Thomas takes from Aristotle, indicates that the soul is denominated from a variety of vital operations of which we have a privileged experience in ourselves. To wish, to fear, to love, to think, to see, and so forth are activities of our own whose existence we are not likely to doubt. If we perform these activities, we must of course be capable of performing them, and the actual performance is not equatable with the capacity since sometimes we perform them and sometimes not. This is the origin of talk about potencies or faculties of the soul: we have various capacities for vital activities like seeing, hearing, wishing, knowing, and so forth. What is the relation of these capacities to the soul? Is the soul identical with them, a class term signifying them all, or distinct from them? Thomas regards the soul as distinct from these capacities or faculties and as related to them as substance to accidents. One reason he gives for this is that if the soul were identical with a capacity to perform a vital act and if there are several such capacities (and there obviously are in man), then since two things identical with a third are identical to one another, the several capacities would actually be one. But surely it would be odd to identify our capacity to see with our capacity to will or to hear or to think. One can see that the soul is something of an inferred entity and that the procedure is from activities to faculties and from faculties to their subject, the soul.

Since this analysis is considered to be part of natural science and the hylomorphic analysis of natural things occurs at the very outset of natural science at its most general level, we are not surprised to find soul spoken of as a form. It is a kind of substantial form, in other words, and the living thing is thought of as a compound of soul and body. Hence, a further definition of soul as the first actuality of an organic body having life in potency. Now, as was clear above, substantial form and prime matter are not so much substances as they are principles or components of substance. Neither matter nor form is thought of as capable of existence apart from a compound. For Aristotle and for Thomas too the question as to the continuance in existence of the human soul after death comes down to asking if the substantial form which is the human soul survives the dissolution of the human being, this compound of body and soul.

How could this question be answered in the affirmative? First, let us point out that Thomas speaks of kinds of soul insofar as souls are denominated from the characteristic or highest activity of the living thing of which the soul is the principle in the sense of substantial form. So we find Thomas speaking of the vegetative soul, of the animal, or sensitive, soul, and of the rational soul. Man is thought to have the capacities for the vital operations found also in lower things like plants and beasts, but beyond those to have the power of reason, and his soul is denominated from his distinguishing and defining activity. The various vital operations seem to involve the body essentially, since seeing, hearing, smelling, fearing, hoping, imagining, and so forth intrinsically involve corporeal aspects. But is the same true of thinking? Here is the crux of the matter for the question of the immortality of the soul as it is discussed by Aquinas. If a living man performs an activity which does not intrinsically and essentially involve his body, we would seem to have some basis for saying that the soul which is the subject of that activity is not dependent for its continued existence on the body.

On many occasions Thomas attempts to show that the human soul is incorruptible because it is capable of a kind of knowing which reveals that it is wholly immaterial. Question 75 of the first part of the Summa theologiae and the Disputed Question on the Soul might be particularly cited. An indication of his procedure can be had from the following sketch. Thomas will use the hylomorphic model to speak of cognition. (De ver., q. 2, a. 2) Just as in things it is their forms which make them actual and what they are, so to know things can be described as coming into possession of the forms of things, of what they are. Thus, Thomas will define knowing as having the form of another as other. Now to have the form of a physical thing in knowledge is a different kind of possession of that form than is exemplified in a concrete physical thing. When the form or nature of rose is united with matter in the genesis of a rose, the result is a singular rose, this one and not that one. In short, the form is individuated as received in matter. However, when we know what a rose is, when, in Thomas' terminology, the form of rose is received in the mind, the result is not another rose but an intentional form which enables us to know the material rose. Thus, the mode of existence of the form in the mind is an immaterial one. This is the source of the claim that the human soul is in a sense all things (anima est quodammodo omnia) since it can know all things. A physical thing can possess but one substantial form, but the mind can know many forms. "It should be said that the principle of intellectual operation which we call man's soul is an incorporeal and subsistent principle. For it is manifest that man owing to intellect can know the natures of all bodies. That which can know other things cannot be those things in its own nature [oportet ut nihil eorum habeat in sua natura] because that which is in it naturally would impede knowledge of other things as we see that the tongue of someone ill which is infected by a choleric and bitter humor cannot perceive what is sweet but everything seems bitter to it. If therefore the intellectual principle had in itself the nature of some body, it could not know all bodies, for every body has some determinate nature. Therefore, it is impossible that the intellectual principle be a body." (ST, Ia, q. 75, a. 2) can Once more, we face a most difficult matter and a doctrine which be assessed only when all its presuppositions are examined, but this outline may convey something of the flavor of Thomas' procedure. As we have said several times before, the upshot of these two proofs within natural science is that one sees that "being" must be predicated of things which are not material, that the science of being as being is different from the science of natural, or material, being.

F. Metaphysics

Let us begin this section by taking a fairly close look at the preface Thomas wrote to his Commentary on the Metaphysics of Aristotle. This preface sketches the terrain of metaphysics and suggests a numher of points we can develop in order to convey the nature of Thomas metaphysical doctrine.

Thomas begins the preface by remarking that whenever many things are organized into one whole there must be something which directs and orders the many. He illustrates the principle by noting that man is one thing composed of several "parts," namely, body and soul, and that while it is the role of soul to command, it is that of body to obey. All arts and sciences, he goes on to say, are ordered to one thing, namely, to the perfection and happiness of man, but it is necessary that one of them be directive of all the others and, that science will be called wisdom because it is the role of the wise to order: sapientis est ordinare.

We can get some inkling of what this directive science would be and what its subject matter is by pursuing the analogy and asking what makes a man fit to rule others. Well, Thomas says, choosing between brain and brawn, would not we say that men of vigorous intellect are more fit to rule others than are men of great bodily strength but weak minds? Could not we say, then, that the science which is most intellectual is naturally fit to be regulative of others? But what would we mean by the "most intellectual science?" Thomas suggests that it would be the science concerned with the most intelligible objects and adds that "the most intelligible" can be understood in three ways.

First, that which grounds certitude of understanding is what is meant by intelligible. Since to have certitude is to know the cause of what is known, a science which is concerned with first causes can meaningfully be said to deal with the most intelligible things and to be directive of all other sciences which deal with lesser and thus less intelligible causes.

Second, the "most intelligible" can also be explicated by comparing intellection and sense perception. "For, since perception is cognition of particulars, by that very fact it seems to differ from understanding which grasps universals. Hence, that science is most intellectual which concerns itself with the most universal principles -- these are being and what follows on being like one and many, potency and act, which ought not be left wholly uninvestigated since without knowledge of these knowledge of what is proper to a given genus or species cannot be had." Very abstract notions like being, one, act and potency, do not fall to the consideration of any particular science; indeed, since knowledge of them is needed to undertake the study of any determinate type of being, one would have to say that if the study of them falls to one particular science, it falls to every particular science. Better that in all their scope and generality they be treated in one common science which is thereby most intellectual and directive of the others.

Finally, if we consider the nature of intellectual knowledge, which involves abstraction from matter, we can say that the most intelligible things are those most free of matter. What is most free of or separate from matter will not be what is free of individuating characteristics alone, as man is free from the peculiarities found in Socrates, Plato, and so on, nor what is free from all sensible matter in conception alone, like mathematical objects, but rather most free are existent immaterial things, like God and the angels. The science concerned with immaterial things seems most intellectual and, accordingly, directive of the others.

We recall that Thomas started by saying that he was looking for the one science that would be directive of all the others and that this would be the science concerned with the most intelligible objects. Since he has introduced three criteria for understanding "most intelligible," he must go on to show that it is one and the same science that is referred to no matter which criterion of "most intelligible" is used. We are talking, he says, of one science, not three. "For the aforementioned separate substances are the universal and first causes of being [essendi]. It belongs to the same science to consider the proper causes of a genus and the genus itself, as the natural scientist considers the principles of natural body; so it belongs to the same science to consider separate substances, universal being [ens commune], which is the genus of which the foregoing substances are the common and universal causes." If the science considers the three things mentioned, it does not consider all of them as its subject; the subject of the science is being (ens commune). In a science we seek to know the causes and properties of the subject, but the causes of the subject of a science are not the subject of the science. However, though the subject of this science is being in general, it is said to bear on what is separate from matter both in conception and in existence, since this is taken to mean not only what never exists in matter, like God, but also what is sometimes material, sometimes immaterial, like being.

Three names for the science follow from these considerations. It is called "theology" insofar as it is concerned with immaterial existents, the chief of whom is God; it is called "metaphysics" because it comes after physics, which studies a type of being, while metaphysics is concerned with being as being. Finally, it is sometimes called "First Philosophy" because it is concerned with primary realities, first causes.

Thomas has gotten a tremendous amount into this short preface, has in fact taken stands on a number of controverted and difficult questions about the nature of metaphysics and its relation to other sciences. In the sequel we want to unpack this preface a bit and speak of the relation of metaphysics to the other sciences, and of the way in which it is both a general science and a theology. This will lead to a discussion of analogy as an explanation of talk about God.

Abstraction and Separation. When we discussed the division of speculative philosophy earlier, we made use of a text to which we must now return, a text from Thomas' exposition of Boethius' work on the Trinity. In distinguishing types of speculative science Thomas appealed to the nature of the speculable, which he characterized as immaterial, and argued that insofar as speculable objects are more or less separated from matter, the sciences which deal with them will differ formally. The various degrees of immateriality are revealed in definitions. This is important since the model of scientific knowledge is a demonstrative syllogism whose middle term is the definition of the subject of the conclusion that links it with its predicate, a property. The order of removal (ordo remotionis) from matter is called by Thomas, in article one of Question Five of the Expositio, a separation (separatio), and here the term covers indiscriminately the kind of freedom from matter exhibited in the objects of natural science, mathematics, and metaphysics. In article three the term "separatio" acquires a narrower meaning which restricts its application to metaphysical abstraction, a fact which has occasioned much discussion.

There are four articles in question five of the Expositio. After the distinction of the different kinds of speculative science in article one the remaining articles take up, in order, natural science, mathematics, and metaphysics. Article three, therefore, is concerned with mathematics, but recent discussion has turned on the remarks on the nature of metaphysics to be found there. The guiding question of the article is, Does mathematics consider without matter and motion things which exist in matter? Let us turn immediately to the body of the article. Aquinas begins by saying that there are two kinds of abstraction which follow on two kinds of intellectual activity: simple apprehension, and composition and division. The first is that whereby we grasp what things are and is expressed in definitions. Notice that he says these are two kinds of abstraction.

The first kind of mental activity, he continues, looks to the very nature of a thing according to which the thing understood has what rank in reality it has (aliquem gradum in entibus obtinet), whether it is something complete like a whole or incomplete like a part or accident. The second kind of mental activity mentioned looks to the very being of the thing (respicit ipsum esse rei) which in compound things results from the conjunction of its components or principles and in simple things is a concomitant of nature.

Truth consists in the mind's conformity with reality; consequently, we cannot truly abstract one thing from another by means of the second type of intellectual activity when they are united in reality. The reason for this is that abstraction would here be expressed in a negative judgment: A is not B. "By this type of activity the mind can truly abstract only those things which are separate in reality, as when we say, 'Man is not an ass.'" Throughout this discussion of composition and division Thomas uses "abstrahere" to signify the mental act of negative judgment and "separatia" to signify otherness in reality.

The first type of mental activity, the apprehension of the nature of a thing, is relatively freer from reality, so to speak, insofar as something can be understood and defined without reference to things with which it exists. This is not total freedom, of course. The part as part cannot be understood without reference to its whole or the accident without reference to its subject or the parent without reference to children. But of two things which exist together, "if the one does not depend on the other with respect to what constitutes its nature, it can be abstracted by the mind from the other and understood without it." Some parts can thus be understood without their wholes, as letters can be considered apart from syllables, though not vice versa, and accident apart from a determinate subject, like whiteness.

Up to this point, again, Thomas uses "abstrahere," "to abstract," both for negative judgments, the denial that one thing is another or with another, and for conceiving or considering which would be expressed in a definition. He now introduces a new term, "distinguishing" ("distinguere"), and speaks of distinguishing one thing from another in such a way that the phrase comprehends the two kinds of abstraction mentioned. This permits him to give abstracting and separating narrower meanings according to which they are opposed to one another as types of distinguishing. "Sic ergo intellectus distinguit unum ab altero aliter et aliter secundum diversas operationes." The narrow meaning of "separation" confines it to the distinguishing proper to the second type of mental activity, that expressed in a negative judgment. Here one thing is distinguished from another when it is understood not to be with the other (quia secundum operationem qua componit et dividit, distinguit unum ab alio per hoc, quod intelligit unum alii non inesse). Conceptualization, the understanding expressed in a definition, may be called abstracting in a narrower sense, namely, when one thing is understood, without another, though the two are together in reality (sed tunc tantum quando ea quorum unum sine altero intelligitur sunt simul secundum rem). In this narrow sense an animal is not considered abstractly when it is considered apart from stone, since they are not one in reality; examples of abstraction in the narrow sense would be considering a form apart from matter and considering a whole without its parts.

The thing that has interested scholars here is the fact that Thomas goes on to speak of natural science and mathematics in terms of these two kinds of abstraction in the narrow sense, applying the consideration of form without matter to mathematics and of a whole without its parts to natural science. This would seem to leave separation in the proper, or narrow, sense to metaphysics, and the conclusion to be drawn is that metaphysical thinking involves a negative judgment, an assertion that in reality something is separate from something, is independent in existence from something else. We know from the foregoing what central negative judgment provides the charter for metaphysics. It is precisely insofar as we can judge that some being is separate or independent from matter in existence that we can say that a science of being as being is possible, a science which will be distinct from natural science, which is concerned with a particular kind of being, mobile or physical being. (And of course we know natural science is a particular science, that is, a science concerned with a particular kind of being, just insofar as we know there is another kind of being.) This science will differ from mathematics, which, though it defines its object without sensible matter, does not assert that it so exists out-there.

Being as Being. The subject of metaphysics is being as being; metaphysics inquires into what pertains to being, not insofar as it is mobile and material, but precisely insofar as it is being. It is concerned with separate being, with whatever can be considered apart from all matter and asserted to enjoy existence in separation from all matter. Now, all this sounds extremely enigmatic, particularly when we try to put together various statements of Aquinas. When he says that there is a science of being as being he is talking of wisdom, the culminating philosophical consideration, that which is appropriately placed last in the order of learning the sciences since it would be folly to expect wisdom until one had studied for a long time. Yet Thomas will also say that being is the first thing we know (ens est quod primum cadit in intellectu), an observation that suggests what anyone would expect, namely, that to know of something that it is, that it is a being, is to know as little of it as is possible. But does not the description of metaphysics as wisdom suggest that to know being as being is the most profound and desirable knowledge possible?

The difficulty we are trying to elaborate can be put in another way. Is metaphysics a general science of being, an ontology, or is it rather a science of a particular kind of being, immaterial being, and thus a particular science, a theology? Remember that in the preface to his Commentary on the Metaphysics Thomas had said that metaphysics is concerned both with things which never exist in matter (like God and the angels) as well as with things which sometimes exist in matter and sometimes do not (like being, substance, act and potency). Does this solve our problem? It would seem not, since if substance is defined without any matter, the definition would be appropriate only to separate substances, and once more metaphysics would seem to be a special science, not a general science of all being.

As it happens, Aristotle raised just this question in book six of his Metaphysics. Let us consider Thomas' formulation of the problem and its solution. "Someone might wonder if First Philosophy is universal, concerned with being generally, or if it considers some determinate genus, some one nature (which does not seem to be the case) Unlike mathematical science, which deals with a determinate kind of things, "First Philosophy is universally common to all things." (In VI Metaph., lect. 1, n. 1169) Metaphysics then would seem to be about everything insofar as everything has something in common with everything else, namely, being. But would not such scope entail meager and impoverished knowledge? Here is Thomas' formulation of the solution. "If there were no substance other than those which exist in nature [secundum naturam] with which physics is concerned, physics would be the first science. But if there is an immobile substance, this kind will be prior to natural substance, and the philosophy considering it will be First Philosophy. And because it is first, it will be universal and it will fall to it to consider being as being. . . . The science of the first being and of common being is the same." (Ibid., n. 1170)

The solution seems to retain the difficulty. This science is concerned with the first being, presumably God, and therefore must be concerned with common being. Common being is not a synonym for first being here; it seems to stand for being insofar as it is predicable of all that is, both immaterial and sensible things. Earlier Thomas had written, "Notice however that although things which are separate both in definition and in existence from matter and motion pertain to the consideration of First Philosophy, not only such things do, but sensible things as well, insofar as they are beings [in quantum sunt entia]." (Ibid., n. 1165)

Being considered universally (ens commune), being as being (ens in quantum ens) -- these signify the subject of metaphysics, and the subject of the science is that about which we want to discover attributes or properties which belong to it because of what the subject is. What does Thomas mean by "being," what is the "ratio entis"? He answers this question in a number of ways: what is, what has existence (quod est, habens esse, id quod habet esse). Such a definition does not include sensible matter, but neither does it exclude sensible matter in the sense of prescinding from it. Thus, with this meaning "being" can be predicated of Socrates or a rose, but it surely would not tell us a great deal about them. Far better to know of Socrates that he is a man, of a rose that it is a plant -- better in the sense of more informative. If that is true, and surely it is, what kind of an advance is metaphysics supposed to be? To answer that question we must draw back a bit and ask ourselves what for Thomas is the ultimate and crowning concern of philosophy. Philosophy drives toward knowledge of the divine, toward knowledge of God, and this is preeminently the concern of metaphysics. Metaphysics is not undertaken to give us more adequate and appropriate knowledge of physical things (if there were no immaterial substance, physics would be first philosophy); it is undertaken to give us less inadequate knowledge of the divine. The formulation "being as being" therefore should not he regarded as a more profound approach to physical or sensible beings. To know sensible beings insofar as they are beings (in quantum sunt entia) is simply less informative than to know them as sensible (in quantum sunt sensibilia). The whole point of formulating definitions of "being" and "one" and "act" which do not include sensible matter is to provide us with a less inadequate language with which to talk about God. It would seem that for Aquinas it is not even the principal business of metaphysics to prove the existence of God, since for him that is one of the presuppositions of metaphysics. Rather, for Aquinas metaphysics would seem to be a prolonged reflection on what we know of sensible being, a purification of concepts formed in knowing sensible beings so that they become means of describing less inadequately the immaterial or divine. This interpretation of the metaphysics of Aquinas may be novel, but I feel it accurately reflects both what he says about metaphysics and what he does as a metaphysician. In reply to the earlier question, we can say that for Thomas metaphysics is an ontology in order to be the only kind of theology it can be. God, simple substance, cannot be the subject of a science, Thomas argues, so metaphysics cannot be a theology in the sense that God is its subject matter. Its subject matter is being as being, that is, conceptions which do not involve sensible matter and thus are inadequately informative of sensible things but which, because of this absence of matter, provide a less inadequate bridge to talk about God.

The Analogy of Being. It is a commonplace that for Thomas being is analogous, but, before discussing his teaching on this point, it must be clear to us what analogy is for him. What are we saying when we say that being is analogous? Ultimately what we are aiming at is the fact that some beings are substances and some are accidents, that some being is finite and one infinite, but while all this is what analogy is applied to in this instance, that is not what "analogy" means. In order to get at the type of word "analogy" is, we might consider another sentence, "Being is a genus." Thomas agrees with Aristotle that that sentence is false, but we have already seen the type of predicate "genus" is, we know what it means to say that "genus" is a logical term. Well, "Being is analogous" is the affirmation Thomas offers when he decides that "Being is a genus" is false. "Analogy" must be a logical term too, and if we imagine three statements each of whose predicates is a logical term -- "being is analogous," "being is univocal," and "being is purely equivocal" -- Thomas will say that only the first is true.

As a logical term, "analogy" signifies the relations among several meanings of a given word; analogy is a kind of signification, and it is usually exemplified by "healthy." Consider the following list: (1) Fido is healthy, (2) urine is healthy, (3) food is healthy. Although the same term occurs as predicate in each of these sentences, it does not seem to have the same meaning in all of them as "man" does in "Socrates is a man" and "Plato is a man." Nor does it seem to have entirely unrelated meanings as "top" does in "he spins the top" and "he opens the top." That is, the meanings of "healthy" in our list, while different, seem related. "Healthy," to use Thomas' language, is imposed to signify from health, and we might formulate a common meaning for the various uses in (1), (2), and (3) above by saying that "healthy" means "related in some way to health" or "referring to health in some way." This would be what Thomas means by the common notion (ratio communis) of an analogous name, but unlike the common notion of a univocal term (the example of "man" above) it does not apply equally to the things of which it is predicated. By applying equally Thomas means that when I say Socrates is a man I make no reference to anything else called a man, something else that might be thought to have prior right to the name. The common notion of the term Thomas calls analogous is unequally common to many things in this sense, that it applies to one thing primarily and to others secondarily. That is, beyond the ratio communis of "healthy" (referring in some way to health), we can formulate a proper notion (ratio propria) which expresses a determinate reference to health, say, "subject of health," which is the principal meaning of the term and is the meaning it has in (1). In (2) it would mean "sign of health," and in (3) "preservative of health." However, if for an analogous term there is a common notion and also a number of determinate notions or meanings, these determinate meanings are fashioned in such a way that one of them is controlling or privileged, the focal meaning of "healthy." In our list the focal meaning (ratio propria) or primary analogate is "subject of health." Why does Thomas say this? How does he know one meaning is more basic than the others? He arrives at this by observing that in explicating the meaning of "healthy" in (2) he must make reference to the meaning it has in (1). Thus, its meaning in (2) is "the sign of health in the subject of health," and its meaning in (3) is "preservative of health in the subject of health." Its meaning in (1) makes no reference to its meanings in (2) or (3), and we can safely conclude that the meaning "healthy" has in (1), "subject of health," is the primary and controlling meaning.

"Healthy" is an example of the analogical community of a term, just as "animal" would be an example of genus. The doctrine of analogical signification is no more tied down to its examples than is any other logical doctrine -- and no less so. As a logical relation, analogy is a second intention and thus is a relation obtaining among real things (or other logical entities) as they are known by us. "Healthy" is one instance of an analogous term, "being" is another. To say of such terms that they are analogous is to say something of the way they are predicated of a variety of things, but just as "genus" does not say something about animal as it exists in reality, apart from our knowing animal nature, neither does "analogy" refer just as such to things as they exist, but as they are known and named by us.

Before going on to "being," we might formulate the technical language Thomas uses in discussing analogous signification. What the term is imposed to signify, health in the ease of "healthy," is called the thing signified, or res significata; the various ways of signifying it, the modi significandi, make up the determinate meanings or rationes, of the term, one of which is primary (per prius), the others secondary (per posterius). What is called the common notion (ratio communis) is quite indeterminate and might be thought of as involving the thing signified and a place-marker for determinate modes of signifying it, something like "health," where the blank can be filled by "subject of," "sign of," and so forth, though, again, one mode of signifying will he controlling and enter into the secondary modes of signifying the res significata. Let us watch Thomas apply all this to being.

The common notion of being is "that which exists," so that existence (esse) is the res significata, and "that which" (or "having" in "having existence") may be regarded as a place-marker for determinate modes of being. That there are different ways of being may be recognized by constructing a list in the way we did with "healthy": (1) George is a man, (2) George is tall, (3) George is tan. This list does not look like the earlier one since we seem to have three different predicates, "is a man," "is tall," "is tan." Nevertheless, these predicates express different modes of being, different ways of existing -- the substantial, quantitative, and qualitative, respectively -- and we could say that our list suggests another: (a) substance is, (b) quantity is, (c) quality is, which suggests a further list: (i) substance is being, (ii) quantity is being, (iii) quality is being. "Being" now emerges as the common predicate, and, as in the case of our list of sentences where "healthy" was the common predicate, Thomas holds that "being" cannot mean exactly the same thing in (i), (ii), and (iii). What the term is first predicated of, the primary analogate, is substance: the mode of signifying esse involved in the predicate of (i) is the ratio propria entis, the controlling signification: "That which exists autonomously, not in another" (id cui debet esse in se et non in alio). The other ways of signifying esse involve reference to the substantial mode of being and thus are secondary meanings of the term. The analogy of "being," therefore, tells us of the way the term "being" is common to many things according to an ordered variety of meanings. The ways of signifying esse express, of course, various ways of being, modi essendi; the various meanings of "being" express various modes of existence. Thus, though the relation of the meaning of "quantity" to the meaning of "substance" is logical, the dependence of accident on substance is real and ontological. That is why. mistakenly, the analogy of being is often understood as a direct statement about the way things are. The coincidence here between the primary meaning of "being" and what primarily is, substance, is, from the point of view of analogical signification, just that, a coincidence; the principal meaning of a term is often ontologically secondary since priority and posteriority among the meanings of a term reflect the process of our knowing and not directly the ontological hierarchy.

Being and Essence. In the foregoing we spoke of the community of being in such a way that we seem unable to account for talk of logical entities or beings, nor do we seem able to account for what Thomas called "being in the sense of [being] true" (ens verum). For example, "There is no one in the room." "There is" means that it is true to say that no one is in the room. This is a secondary sense of "being," as is also the case when logical relations are called beings; the primary sense of being for Thomas is real being (ens reale), being out-there. That real being has many senses is what we were trying to show in our talk of the analogous predication of being with respect to substance and accidents. We might also say that being is analogously common to real being, being as true and logical being on the basis of a list like (1) John is a substance, (2) "the President is not here" is true, (3) analogy is a second intention. The meaning of "being" that could be formulated on the basis of (2) and (3) would make reference to that which could be formulated on the basis of (1), and the reverse would not be the case.

Of real being Thomas will say that it posits something in reality (aliquid in re ponit), so we might call it positive being. That owing to which it "posits" is its essence: only real being is said to have essence. Thus, as Bobik has shown, the title of Thomas' opusculum On Being and Essence suggests just this transition from being as comprehending more than real being to real being which alone possesses essence. And, since real being is analogous and substance is the primary kind of real being, essence will be found par excellence in substance. Essence is that through which and in which a thing has being; we can see the connection between essence and the modes of being (modi essendi) expressed in the various meanings of real being. The essence or nature of a substance is that which makes it what it is and is the measure of its actuality or esse.

This brings us to Thomas' teaching on the relation between the essence and existence (esse) of a substance. This is often presented as a novelty of Thomistic metaphysics, but it should be pointed out that Thomas himself exhibits no sense of being an innovator when he holds that essence and esse must be really different. He attributes the distinction to Plato, Aristotle, and of course Boethius. It is in the De hebdomadibus of Boethius that Thomas finds what he takes to be a capsule statement of the real distinction: diversum est esse et id quod est (to be and what is differ). In Aristotle a phrase which conveys the point is found in the second book of On the Soul: vivere est esse viventibus (for living things to be is to live). Thomas approaches the matter by saying that the essence or nature of a physical substance is composed of matter and form; neither of these alone is the nature of the thing. For a thing of such a nature to exist is for there to be a conjunction of its essential components or principles (ipsum esse ret resultat ex congregatione principiorum rei in compositis). (De trin., q. 5, a. 1) In a living thing essence is composed of body and soul, and this conjunction makes the thing live. To live is of course a determinate kind of existence following on an essence of a given type. When Thomas speaks of a distinction between essence and esse, he does not mean simply that there is a difference between a possible man and an actual man; he does not mean simply that there is a difference between the abstract nature (for example, humanity) and a concrete instance of it (for example, this man). What he intends is this: in an actually existing substance we cannot identify its essence or nature and the actuality or existence which is a consequence of the essence and measured by it. The essence of a thing relates to its esse as potency to act. Thus, Thomas will say that esse is the actuality of all other acts, even of forms. The form is act with respect to matter as potency, but for the act which is form actually to be in matter is an act other than the act the form is. This absolutely fundamental actuality is what Thomas means by esse, and it can be equated neither with form nor with essence in material substances.

The nonidentity of essence and esse does not obtain only in physical substance however; Thomas holds that there are immaterial essences other than God, and as other than God their existence is dependent on God as cause. In such substances essence is identified with form, and the form is regarded as having esse, sharing in it, participating in it in such a way that their essence is other than their existential actuality. In order to pursue this we must first turn to what Thomas has to say about the names of God.

God and Language. We have said that the whole thrust of philosophy and a fortiori of metaphysics is, for Thomas, toward knowledge of God. how such knowledge is possible and how it can be expressed in language are two sides of the same coin, and for purposes of this sketch we will concentrate on the linguistic side.

In question thirteen of the first part of the Summa theologiae, Thomas discusses the divine names, the meaning of terms predicated of God. Some such terms pose relatively little difficulty, for example, what Thomas calls negative names. Thus, when we say of God that he is immaterial or immobile, we may be thought simply to be denying of God certain characteristics of material creatures. Problems of a more pressing sort arise in the case of affirmative names. Let us take "wise" as our example. It should be said in the first place that Thomas approaches the question of talk about God by assuming that the problem arises because a term is predicated both of God and creature, that is, that we are confronted by "Socrates is wise" and "God is wise" and ask ourselves if the predicate has the same meaning in the two uses. Thomas will say that it does not have exactly the same meaning, but neither does it bear utterly unrelated meanings, that is, neither univocity or equivocity seems to handle the case. Well, we know what remains for Thomas: he will say that "wise" is predicated analogously of God and creature. Let us try to explicate this example in terms of what we have already learned about analogical signification.

What would the common meaning (ratio communis) of "wise" be? Surely something like "having wisdom." Thus, wisdom is what the term "wise" chiefly signifies, its res significata. How is wisdom signified when Socrates is said to be wise? The modus significandi here would be somewhat elaborate: to say that Socrates is wise is to say that he is a substance possessing a quality of cognition such that he assesses everything in the light of what is truly first and important. That cannot be the way wisdom is signified when we say that God is wise, if only because in God, who is simple, there is no distinction between substance and accident. To be wise is an accidental attribute of Socrates, but if God is wise and wisdom is no accident in him, we might want to say that God is wisdom. This is quite a different way of "having wisdom" than is the case with Socrates, and the term "wise" must be construed to convey this difference as it is affirmed of God.

Thomas invokes the procedure of Pseudo-Dionysius here and suggests that there are various "moments" in our analysis of the meaning of "wise" in "God is wise." First, there is the affirmation (via affirmationis), but we then go on to deny of God (via negationis) the way of being wise that is expressed in the meaning of the term as affirmed of Socrates, for example. Thus, as is generally the case with analogous predicates, there is the same res significata but different modi significandi. As to how the res significata, wisdom, is found in God, we do not know. We say that it is different from the way it is found in creatures for the reasons given, and this is all quite negative. Finally, we can say that the perfection exists in God in an eminent way (via eminentiae). Nothing in what the term "wise" means (its res significata) prevents our attributing wisdom to God, but we cannot have anything like determinate knowledge of the way (modus) this perfection is found in God. This is why Thomas will say finally that we know what God is not rather than what he is. This is not a charter for calling God anything whatsoever, of course, since it is a consequence of analysis and reflection rather than a refusal to undertake them.

Participation. Let us turn now to the question of "being" as predicated of God and creatures so that we may rejoin our earlier discussion of the real difference between essence and esse in simple substances other than God. We have already seen how the term "being" is common to substance and accidents; the question now is, How is it common to God and creature, to infinite and finite being? The sentences to compare, accordingly, are "Socrates exists" and "God exists," or "Socrates is a being" and "God is a being." The res significata of the term is esse, and in the case of physical substance esse is an actuality consequent upon the conjunction of its essential principles, matter and form. This mode of being cannot obtain in God, and his mode of existing is approached by denying of him the creaturely mode of existing. God is thus thought of as existing in an eminent way, to be existence. This kind of talk leads to a distinction between essential being and participated being.

The common notion of being -- having esse -- has to be so strained when we call God being that it becomes "is esse." Creatures, on the other hand, have esse and in various ways; they partake of esse. To participate or partake means, etymologically, to take a part of, to share in, to possess in a diminished manner. To be something essentially, as opposed to by participation, means to be it wholly, completely, and in an unrestricted fashion. When creatures are called beings by participation, when they are said to participate in esse, the following is what is meant. esse means actuality, but no creature is actuality tout court: any creature is this kind of thing or that, and its nature is consequently the measure of its actuahty. From this point of view, essence as we have discussed it emerges as a limitation on the actuality esse is, and esse is considered abstractly as actuality without qualification.

Now, of course, the essence of a given thing is not a limitation of its esse, since it is precisely the measure of the kind of esse appropriate to it. We must proceed with delicacy here since it is precisely at this point, it seems to me, that some champions of the Platonism of Aquinas have gone astray. The creature's esse is either esse substantiale or esse accidentale, substantial existence or accidental existence. esse substantiale is simply a general and abstract phrase which covers to be alive or to live, which, in turn, is generic with respect to the esse or ultimate actuality of man, beast, and plant. From the point of view of richness of information it is far more exact to say of a living thing that it lives than that it exists (vivere est esse viventibus); in short, more and more determinate designations move us in the direction of greater and greater determinate perfection. There is no doubt that this is true of creatures, but when we attempt to talk about God, we seem to reverse the procedure and put a premium on vagueness.

This can be seen when we consider Thomas' discussion of "being" as the most appropriate, or least inappropriate, name of God. When we say of God that he is a being, as opposed to wise, merciful, and so forth, we seem to be saying the least possible about him. But to say the least possible means here that we are making no reference to determinate creaturely modes of existence, modes which restrict and limit esse considered abstractly as actuality or perfection. It is this very freedom from determinate creaturely modes of being which makes "being" the least inappropriate name of God. And since God does not partake of esse, does not have actuality in some restricted mode, we can speak of God as subsistent existence (ipsum esse subsistens).

The Platonic, or Neoplatonic, aspect of this approach is evident when we see Thomas speaking of a generic expression of esse as if it contained in an eminent manner the specific types of esse below it; as if "to live" were not a vaguer expression of the type of esse appropriate to men or beasts or plants, but a richer concept, containing eminently the subtypes. On that assumption we can press on and think of "to be" (ipsum esse) as containing telescoped within itself all determinate types of esse substantiale and indeed of esse accidentale. esse then becomes a kind of dialectical limit at which various kinds of actuality are considered to meet in an eminent way -- what Cusa will call a coincidentia oppositorum. In Fabro's phrase, esse has then become esse ut actus, the fullness of actuality, as opposed to esse in actu, minimal or brute being-there, mere factual givenness. Esse ut actus, a dialectical construct, provides us with the least inadequate name of God, for when we say he is existence, we are saying that he is total perfection and actuality and no more -- that is, without the diminution and restriction which in creatures is read from their determinate natures or essences. Anything other than God has only as much actuality and perfection as its essence permits. In short, everything other than God partakes of esse, has from the point of view of total perfection only a partial perfection, its own limited one. That is how Thomas establishes the difference between essence and esse in simple substances other than God.

* * *

When the metaphysics of Aquinas is regarded as a lengthy meditation on what man can know of God, which is what essentially it is, something can be seen of what Maritain has called la grandeur et la misère de la métaphysique. In metaphysics man is straining against the limits of his knowing powers, so much so that Aristotle spoke of it as something inhuman, in the sense of superhuman. For Thomas the proportioned object of the human mind is the essence of sensible things, and it is what man knows of the material world which must always provide the lens through which he attempts to see beyond the material world. The elaboration of the subject of metaphysics, being as being, is an effort to formulate concepts which will be less obscure lenses, but their obscurity remains dual: when we consider the physical world through such concepts, we see it more vaguely than we do when we look at it through the more appropriate concepts of natural science; when we use them to gain some purchase on the divine, we are brought to the melancholy realization that all our concepts, all our names, are defective with respect to their mode of representation (quantum ad modum significandi, omne nomen cum defectu est). ( I Contra Gentiles, ch. 30). And yet a little knowledge of the divine, no matter how defective and distorting, is infinitely preferable to much clear and certain knowledge of lesser things.

G. Moral Philosophy

In speaking of the division of philosophy into speculative and practical, we pointed out that for Thomas there are three criteria to which attention must be paid in assessing whether an instance of knowing is speculative or practical, namely, object, method, and end. The object of practical knowledge is called generically the operable, something we can do or make. The types of operable object call attention to the distinction between man as moral agent and man as artisan. The process of making something, of art, is one whose perfection is to be found in a product beyond the process producing it. Thus, Thomas will say that art aims at the perfection of the artifact and not at the perfection of the artisan as man. Of course, a man who makes good shoes would be called a good shoemaker, but one can be a good shoemaker without being a good man in the moral sense. Doing or the do-able (agibile) -- it is with this that our choices and decisions have to do, and the perfection of our choices is the perfection of us as choosers. The standard of perfection here will not be the demands of an artifact. Thomas will emphasize the difference between art and prudence, or practical wisdom, by saying that we can choose the end of art, that is, to make artifacts and to make this one as opposed to that, but in an important sense the end of practical wisdom chooses us, imposes itself upon us. Of course, to act as an artisan, to make things, is something so natural to man that we must say that it would be impossible for man not to be an artisan in the sense this term has for Thomas. His point would seem to be that beyond the englobing necessity, the direction of such activity, the end it seeks to produce, is quite arbitrary and up to us. It is not like this with moral decisions, as we shall see.

Earlier we offered a description of practical knowing according to which its perfection involves the perfection of something other than mere knowing. The perfection of moral knowledge lies in its direction of voluntary acts, of choices. What perfects is a good, and moral philosophy begins for Thomas with the asking of the question, What is the good for man, what is his perfection? Since the good or perfection is looked upon as relative to a process, that which is sought in an act of becoming, the question could be stated, What is man's ultimate end? On the philosophical level Thomas is here a faithful student of Aristotle. For purposes of moral philosophy man is something that comes to be, something striving for its good and doing this in a conscious way. Unlike other cosmic entities, man, though fashioned for a given purpose, is not directed toward it in an unconscious and willy-nilly way. Rather, it is the mark of man that in reflecting on himself in his voluntary activity he asks what is the purpose of such activity, in what will its perfection consist? For a man to act or to do is for him to know what he is doing. The question "Why are you doing that?" might never be addressed to a being less than man, but it is always a good question to put to him. The implication of the question is that man is consciously directing himself to certain ends or goals. This can be taken to be a given of moral philosophy: we do make choices, we do pursue goals. The question of moral phi]osophy is, How can we do this well?

One could give a first statement of the human good in terms of what has already been said. The human good is to do well man's characteristic activity. Since this characteristic activity is reasoning, performing it well is man's good, and virtue is the term which designates the perfection of an activity. Thus, Thomas, like Aristotle, will say that virtuous rational activity is the human good. That is, as Aristotle observed, little more than a platitude, but it does involve a discrimination among possible answers to the question, What is the human good? Man houses not only reasoning but also a desire for pleasure, an impulse to avoid physical harm and pain. He is also the seat of any number of acts of sensation of various kinds. Yet more basically, he grows, takes nourishment, moves from place to place. Man on this basis comes to be regarded as a kind of epitomization of processes which are found in lesser beings as well, for it is not man alone who moves and grows, who senses, who seeks pleasure and avoids pain. But man, to do these humanly, must do them rationally insofar as such activities are amenable to rational control. To seek pleasure in a human way is to subject the objects which give physical pleasure to a goal beyond themselves and so to assess them; to seek pleasure pell-mell and irrationally is possible for man, but could a man who did this be considered a good man? Not if the mark of man is to use his reason, for then the specifically human good must attach to what is peculiar and characteristic of man.

"Reasoning" must be distinguished, however. There is the process of reasoning itself, with its appropriate objects and perfection; there is also reasoning which bears on activities other than reasoning and seeks to perfect them. The latter is practical reasoning, and it is when man's appetite is responsive to such rational direction that we have the perfection of rational activity which is called moral virtue. A life lived according to reason -- that is the human good -- and this covers a multitude of virtues: the human pursuit of sensual pleasure, a human avoidance of physical pain. That is, when instinctive processes become permeated with rationality, they are more fully human. A life lived for pleasure is not a human life because the objects of pursuit which cause physical pleasure are not peculiar to human appetition and because human appetition, in a broad sense, encompasses other and higher objects than these.

To talk of the end or goal of human or rational choice may seem to refer to consequences of choice, to some quietus, some state achieved when choice is done. The human good, as Thomas sees it, is not beyond action, but in action; it is the style or formality or quality of our choices. To be a man is to choose and decide and live, and to do these things well is man's goal or end, and it will be had, if it is had, in acting and choosing and deciding, not after these are done. That is why Thomas will agree with Aristotle that man's happiness is an activity, not a state or capacity.

Man's moral goal is fixed Thomas holds; he has no choice concerning what will, in the nature of things, perfect him and be his good. Since he is a rational agent, his perfection can only be the perfection of rational activity. Rational activity can be either pure reason or practical reason, and it is the latter that is the concern of moral philosophy. The perfection of practical rational activity, again, is what is meant by moral virtue. To say that man's good is fixed by his very nature means that a man cannot be perfected as man by the pell-mell pursuit of pleasure, for example. Such an activity is not commensurate with human nature.

Thomas calls judgments or precepts concerning what we must do which are anchored in our nature, and thus sure and inflexible, natural law precepts. He uses the plural. (ST, IaIIae, q. 94, a. 2) Thus far, we have seen one such precept, which may be stated normatively as: Act virtuously. Thomas will sometimes state this overriding precept of human moral activity in the following way: Do good and avoid evil. But of course one must understand that in terms of the human good, and when one does, "act virtuously" is synonymous with "do good" as this is addressed to man. Are there any other natural law precepts? We can get a plurality of precepts which will have the fixity of the generic one just mentioned by appealing to the tradition of the cardinal virtues. Temperance is the name given to the rational control of the appetite for objects which cause physical pleasure. Fortitude, or bravery, is the name given the rational control of the impulse to avoid objects which cause physical pain. Justice and prudence are the other two cardinal virtues, and, without going into the nature of these, we can suggest that "Be temperate," "Be brave," "Be just," and "Be prudent" are precepts which always bind a man. Their plurality is gained by articulating the regions of human activity in which rational direction is required. There will never be a time when temperance, bravery, justice, and prudence will not be the guiding ideals of human choice. That is what is meant by saying these precepts are fixed, unchanging, and so forth.

Of course, the great difficulty in human action is not in settling on the major guidelines of choice. The difficulties begin when we ask, "But how should I be temperate in such and such circumstances?" And so too with bravery, justice, and prudence. If we think of these cardinal virtues as the articulation of man's good or end, the further questions can be said to deal with means of incorporating these ideals of human conduct in our lives in the particular decisions we must make.

The precepts of natural law are judgments in the practical order analogous to self-evident judgments in the speculative order. A mark of the self-evident judgment is that to contradict it lands one in absurdity, and with respect to the most basic such judgment, the so-called principle of contradiction, the denial of it requires one to employ it. Something like this may be said about the first principle of the practical order, "Act rationally." If one questioned this, he might be thought of as asking a question as to why he should ask questions. For surely one who wants a justification of the principle is already exhibiting in his conduct his acceptance of the rule that he ought to act rationally. The articulation of the human good into the cardinal virtues is such that something of the same kind of imperviousness to contradiction attends such a precept as "Act temperately." If this principle lays on us the obligation to seek pleasure in a manner befitting the kind of agent we are, it would be difficult to gainsay it without calling into question the kind of agent man is and thus the kind of agent the questioner reveals himself to be.

At a level of great universality, then, Thomas feels that there are inflexible guidelines for human choice; the target at least is clear. But how is one to be temperate in such and such circumstances? As soon as we move into the area of enunciating means of realizing our end or goal, our judgments become corrigible, usually as opposed to always true. The elaboration of less general moral judgments not only depends more and more on experience, our own and others, but reflects increasingly the evanescence of circumstances, the particular historical epoch in which such judgments are made. Thomas will insist on the corrigibility and probability of general judgments less than the most common ones of natural law, but at the same time he will argue that this is no reason against the formulation of more particular moral judgments.

There are thus two levels of generality, what we might call the level of principles and the level of rules, with the former certain and inflexible and the latter true, even if true only for the most part or usually. The moral rule may be thought of as a statement of the means whereby we can usually achieve our end. The justification of moral rules, therefore, is to be found in the principles, in the end. But since the rules are true only for the most part, they admit of exceptions. What would justify an exception to a rule if the principle justifies the rule? It seems that we must say that the principle justifies the exception as well as the original rule, since if we should judge that in some cases it would be wrong to abide by a rule having to do with temperance, say, we might so judge because acting in accord with the rule will thwart the end of temperance or of some other articulation of our overriding good. And, of course, the recognition of exceptions to a rule can give rise to the formulation of another and lesser rule.

Since both principles and rules are in the practical order, they are not sought for their own sake but point beyond cognition to the perfection of our choices. Thomas follows the lead of Aristotle in saying that beyond the common principles, naturally and easily knowable, and beyond moral rules which might be taken to be the domain of moral philosophy and of human law, there is a third level of moral knowledge, completely practical knowledge, where we are cognitively engaged in applying principle or rule to a concrete set of circumstances. By calling this area the realm of prudence, completely practical knowledge, we are suggesting that it saves all three of the criteria of practical knowledge mentioned earlier. With Aristotle, Thomas calls the discourse of prudence a practical syllogism.

The practical syllogism, the discourse of practical reasoning in the concrete direction of choices, is analyzed as follows. The major premise is a generality, a principle or rule; the minor premise is an assessment of our present singular circumstance in the light of the principle or rule relevant to it. The conclusion, ideally, is a choice in accord with this assessment. As soon as we move away from the major premise, we move away from generality and into an area where the state of our appetites becomes influential. The principle or rule expresses an object of appetition, a good, at a level of generality, and we can assent to such judgments in a way that does not engage us fundamentally where we live. Practical discourse, the practical syllogism, when it moves into the area of the concrete and singular, will reveal the actual condition of our appetites, what for us is really considered good. Now what for us is really considered good, what we have a bent toward due to past choices, may be other than and in conflict with the good expressed in the major premise. Imagine that the major premise has to do with temperance. We find ourselves in a situation where at the back of our mind we are aware of the obliging character of temperance with reference to our choices; with that awareness we regard the circumstances in which we find ourselves. In doing so we might repress or dismiss the moral principle because of the attractiveness of an object which promises pleasure and go on to pursue that object. This would reveal that the good expressed in the principle or rule is not effectively our good; that our choices are really governed by a rule we might hesitate to express as a generality, namely, "Pursue pleasure mindlessly."

A man acting on such a basis would be incontinent, in Thomas' use of the term; in moments of repose, as a student of ethics, say, he might assent to a moral principle or rule, but when the chips are down, the good he seeks is not that expressed in the moral principle. In order to move from the principle to an assessment of our circumstances in the light of it and to a choice in accord with that assessment, we must effectively love the good expressed in the principle. That is why Thomas will say that the truth of the ultimate practical judgment is to be read, not as a conformity with the way things are, but as a conformity with rectified appetite. In short, only the virtuous man will easily and without pain make the transition in practical discourse from principles to choice. One can see why Thomas places such importance on moral training and upbringing; it makes a great deal of difference what objects of aspiration are placed before us in our early years. Mature reflection on human action always takes place against a background of formation and education, of ideals which have become familiar because of habituation. It is not the case that the ideal can be recognized to be such only by those who strive to incorporate it into their lives, but Thomas will insist that when it comes to how the ideal can be realized here and now, our ability to know this is a function of our past moral history.

We might summarize Thomas' view of moral knowledge, then, by seeing three levels of it. First is the level of the most common precepts, those which enunciate the ideal of rational love or loving reason: man's perfection and its articulation into the cardinal virtues. This is the domain of natural law without qualification, for as long as man is what he is, his perfection is the perfection of the kind of agent he is. On a second level would be the formation of precepts or rules which elaborate at a level of generality how the ideal can usually be achieved. All such rules are corrigible, of course, and they increasingly reflect experience and thus the changing situations in which man strives for the ideal. Finally, there is the concrete level, the singular choice in which knowledge must be proportionate to these changing, concrete circumstances and where knowledge is inevitably influenced by the condition of the agent's appetite.

H. Thomas and His Time

The foregoing presentation of various aspects of Thomas' doctrine has made little effort to relate what he taught to the currents of his day, though of course the reader will have connected elements of Thomas' teaching with controversies mentioned in earlier chapters. Since the fame of Aquinas reposes in large part on the fact that he brought together in a new whole the various strains and traditions which met in the thirteenth century, it is only right that we say some few things about his general attitude as it is exemplified in a number of key controversies.

If the men of the late twelfth and thirteenth centuries had been confronted only with accurate Latin translations of the Metaphysics, Physics, and Nicomachean Ethics of Aristotle, unaccompanied by commentaries, they would certainly have had their work cut out for them; we can surmise that there would have been a good dose of defensiveness in their response to such a powerful statement of the nature of the world, since in many particulars it seems contrary to what the Christian believes to be true. But of course the matter was not at all that simple. The Aristotle who came to be known came together with Islamic interpretations which confused Aristotelian and Neoplatonic doctrines. We have seen that in Islam portions of Plotinus and of Proclus were considered to be the work of Aristotle. Furthermore, the Greek commentaries on Aristotle, with their Neoplatonic bent, came into Latin directly as well as through the medium of the influence they had had on the thinkers of Islam. That meant that the whole Neoplatonic apparatus of emanation and the mediated causality of the first cause were added to the real problems in the text of Aristotle, those associated with the scope of the divine knowledge, the eternity of the world, and the survival of the individual soul after death. Before this onslaught it is not surprising to find that the first reaction was one of caution. Aristotle's works were proscribed at the University of Paris. Balancing this, however, was the commission set up by Gregory IX to study and interpret the teaching of Aristotle. The invitation to seek in Aristotle what truth might be there was clear, and masters responded to it to the detriment of the ban.

One of the members of the papal commission, William of Auvergne, indicates one mode of response to the new literature. He is quite confused as to what is authentically Aristotelian doctrine and what is not, but he has a double measure with which to confront the new teachings. First, there is faith; if the Aristotelians teach something contrary to faith, that is prima facie indication that their teaching is false. William does not leave the matter there, however; he goes on to try to show the falsity of such teachings by arguments. What exercises its influence on him as he does this is the Augustinian tradition which had been dominant, but, unsurprisingly, William also takes over from Aristotle and Islamic thinkers whatever he takes to be sound. The whole into which such borrowings are assumed is somewhat difficult to describe, and to call it traditional Augustinianism is to label it rather than analyze it.

Another attitude, far less ironic, is represented by Bonaventure; yet another by Albert and, more brazenly, the Latin Averroists. We have seen the curious neutrality Albert claims when he is exposing the tenets of Peripatetic philosophy; more curious still is the silence he attempts with respect to the theological verdict on the philosophy he is narrating. His model here seems to be Moses Maimonides, and the term of the attitude could be either that theology must be measured by philosophy or, perhaps, that the truth of philosophy and that of theology may conflict and contradict in a way that is ultimately acceptable.

With Aquinas we have an Aristotelian, a man who accepts the fundamental validity of the philosophy of Aristotle and will employ it as the context into which other contributions must be fitted. This attitude is possible for him because he was able to distinguish between Aristotle and Neoplatonism, between Aristotle and his interpreters, in a way that had not been done to the same extent before. This is not to say that he rejects Neoplatonism, whether that of Proclus or of the Greek and Islamic commentators, out of hand. But there is a new clarity as to what is what. For example, in the proemium to his exposition of the Liber de causis Thomas matter-of-factly states the origin of the work in Proclus; apparently this is the first time the identification was made, and Thomas was able to make it because William of Moerbeke had provided him with a Latin translation of Proclus' Elements of Theology. When he approaches the text of Aristotle, Thomas seems possessed of the certitude that, accurately understood, it can withstand the criticisms that have been directed at it. Let us examine a few instances of this.

In the twelfth book of the Metaphysics Aristotle had said that God knows only himself, and this had been taken to mean that God knows nothing other than himself, which would seem a plausible enough interpretation. From that would follow a denial of providence and so forth, and Aristotle emerges as teaching things inimical to belief. Thomas comes at the passage in question with little indication that it has been the subject of controversy. Aristotle, he explains, identifies the First Cause with his act of understanding and says that the nobility of that act of understanding can be read in terms of its object. The object of the act of understanding (identified with the First Cause) must be itself, since if it were something else, that object would be more noble than the First Cause. But the First Cause is most noble, and so forth, so it is necessary that it understand itself and that in it understanding and what is understood be the same. "It should be considered however that the Philosopher intends to show that God understands, not something else, but rather himself insofar as what is understood is the perfection of the one understanding and of his act of understanding. It is quite clear that nothing else can be understood by God in this sense that it would be the perfection of his intellect. Nor does it follow that other things are unknown by him, since in understanding himself he understands all other things." (In XII Metaphys., lect. 11, n. 2614) The point is put more succinctly in Thomas' discussion of proposition thirteen of the Liber de causis: "Since according to the opinion of Aristotle, which in this matter is more in accord with Catholic doctrine [more than the opinion of Proclus, that is], we posit, not many forms above intellect, but one alone which is the First Cause, we must say that just as it is its existence [ipsa est ipsum esse] so it is one with its life and its intellect. Hence, Aristotle in the twelfth book of the Metaphysics proves that he [God] understands only himself, not that knowledge of other things is lacking to him, but because his intellect is not informed by any intelligible species other than himself. What Thomas is doing in such a case is, not bending Aristotle to Catholic doctrine, but insisting that Aristotle correctly understood is in accord with the faith. So too, for Thomas, Aristotle's God is the creative cause of the universe. "From this manifestly appears the falsity of their opinion who hold that Aristotle thought that God is the cause, not of the substance of the heaven, but only of its motion." (In VI Metaphys., lect. 1, n. 1164) It has become fashionable to say that Aristotle's God is only the ultimate final cause of the world; that "only" would have mystified Thomas, for whom the final cause is, as it was for Aristotle, the causa causarum, the cause of the other causes. Although he never developed the argument, since he was not confronted with this curious notion of "only the ultimate final cause," it would be a simple matter for Thomas to prove that if God is the ultimate final cause of the world, he is a fortiori its first efficient cause.

There is considerable confusion in recent discussions of Aristotle and creation. Sometimes it seems to be suggested that Aristotle's world cannot be a created one because it is eternal. Thomas is quite sure that it was Aristotle's firm opinion that the world is eternal, but he insists, as others had, that the arguments he brings forward for this claim are at best probable. Would the eternity of the world preclude its being a created world? This was a matter Thomas investigated, notably in an opusculum entitled On the Eternity of the World Against Murmurers. For those who take this sort of thing to be a mark of humanness, we might observe that in this opusculum Aquinas treats his unnamed adversaries with sarcasm, saying how marvelous it is that men like Augustine and the best philosophers had not seen the contradiction involved in an eternally created world. Those who see a contradiction in the notion, he adds icily, must alone be men, and wisdom arrived in the world with them.

In the opusculum On the Unity of the Intellect Against the Averroists Thomas goes to great lengths to show the inaccuracy of the Averroistic interpretation of Aristotle's doctrine on the faculties of the soul. Perhaps nowhere else is it as clear that what is at stake is what Aristotle taught and that accuracy of interpretation goes hand in hand with acceptance of the result. In this opusculum, as in his work On Separate Substances, Thomas exhibits his knowledge of Islamic, Jewish, and Greek interpretations of Aristotle.

We mentioned earlier in this chapter how unwise it is to identify the philosophy of Aquinas and the philosophy of Aristotle when this leads to a failure to recognize the influence of other philosophers on Thomas. It would be far unwiser to suggest that Thomas' thought is in principle Neoplatonic. In its principles Thomas' philosophy is Aristotelian, and, as we have observed, whatever else enters into his philosophy is subjected to an Aristotelian test, is brought into a fundamentally Aristotelian context. One may cheer or lament this, but he may not deny it or ignore it.

Thomas' contemporaries found it difficult to ignore what he had accomplished, and we shall see in the next chapter something of the history of his immediate influence and reactions to it. Insofar as Thomas the philosopher is a model for the twentieth-century thinker, it may be well to distinguish two aspects of the model. On the one hand are substantive doctrines to be understood and assessed; on the other hand there is what can be called the spirit of Thomas. That spirit applied nowadays to the thought of Thomas himself would doubtless see it as a component of a larger whole, and would see the Thomist as a philosopher for whom Thomas functions as Aristotle functioned for Thomas.

Bibliographical Note

Aquinas, Opera omnia in 25 vols. (Parma, 1862-1870); the Leonine edition (Rome, 1882-1948) is not yet complete, but 16 vols. have been published. English translations: J. Rowan, Commentary on the Metaphysics, 2 vols. (Chicago, 1961); Pegis, Anderson, Bourke, and O'Neil, On the Truth of the Catholic Faith (Summa contra Gentiles), 5 vols. (New York, 1954-1956); A. Pegis, ed., Basic Writings of Saint Thomas Aquinas, 2 vols. (New York, 1948); Mulligan, Schmidt, and McClynn, Truth, 3 vols. (Chicago, 1952-1954); J. Bobik, Aquinas On Being and Essence, A Translation and Interpretation (Notre Dame, 1965); a new translation of the Summa theologiae under the auspices of the English Dominicans began to appear in 1964 (New York: McGraw-Hill); Foster and Humphries, Commentary on the De anima (London, 1951); Blackwell, Spath, and Thirlkel, Commentary on Aristotle's Physics (New Haven, 1963); A. Maurer, The Division and Method of the Sciences (Toronto, 1953). Studies on Aquinas are incredibly numerous; the reader is referred to the following bibliographies: V. Bourke, Thomistic Bibliography (St. Louis, 1945); P. Mandonnet and J. Destrez, Bibliographie Thomiste (Paris, 1960); P. Wyser, Thomas von Aquin in the series Bibliographisehe Einfuhrungen in das Studium der Philosophie (Bern, 1950). The Repertoire bibliographique de Louvain (supplement to Revue philosophique de Louvain) is invaluable for philosophical works generally and can be used to bring the above bibliographies up to date. A recent work on the continuing role of Aquinas is R. McInerny, Thomism in an Age of Renewal (New York, 1966; reprint: Notre Dame, 1968).

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