Jacques Maritain Center: Ethics Without God?What is meant by the question: "Can we be good without God?" The question of ethics without God is not the same question as ethics without revelation. Indeed, revelation, at least as interpreted in the Catholic tradition, would hold that one can have an ethics without direct special revelation by God. Certain basic truths in the moral life, such as prohibitions against intentionally killing an innocent person, stealing, and adultery, can be understood without revelation. Although as a mercy to human beings whose minds are darkened by the fall God reveals the Ten Commandments, in principle these truths could be known without revelation.
Before turning explicitly to the Sententia libri ethicorum, I would also like to say a word about the distinction between acknowledging basic moral truths and a systematic exposition of moral truths and address the role of God in each kind of knowing. Grasping basic moral truths is not the same thing as having ethical knowledge, the kind which it would be possible to gain through the study of moral theology or moral philosophy. This distinction between basic moral truths needed to live rightly and a theoretical account of the moral life can be illustrated by the difference between what one must know to be saved and what one must know in order to have a satisfactory account of what is needed to be saved. The necessary intellectual requirements in terms of belief needed to acquire salvation (nearly pure practical knowing) are quite modest according the moral theology of Thomas. One must merely believe in God and in God's providence.{1} On the other hand, an adequate moral theology, that is to say, an adequate account of how God saves his people, involves one in the complexities addressed in the Summa theologiae -- e.g. the relationship of faith and reason, nature and grace, Old Law and New Law, virtues acquired and virtues infused, gifts of the Holy Spirit and fruits of the Holy Spirit, Sacraments and states in life, and so on. In other words, we can distinguish between moral theology considered as a science (which requires extensive knowledge of many things) and what an individual person would actually need to know in order to be saved (which makes quite modest intellectual requirements).
In addressing what is necessary for salvation, Thomas is speaking of perfect happiness, the happiness that is to be had in the next life, not imperfect happiness, that happiness that is to be had in this life by human effort. In order to achieve perfect happiness, the intellectual requirements are quite minimal -- believing in God and in God's providence. Presumably, what is necessary to achieve merely imperfect happiness in this life (the subject of moral philosophy) would be even less demanding in terms of belief in the divine. And it is this form of happiness, imperfect happiness, which Thomas explores in his commentary on the Nicomachean Ethics. Happiness in the present life for Aristotle involves abstaining from morally wrong action. Indeed, one might have correct judgment that murder or adultery is wrong, but not have this view grounded in beliefs about God.
Perhaps, one believes such truths because of the instruction of trusted parents or teachers. Or perhaps one holds the judgment because of an unreflective assumption that whatever most people believe is true should be believed. Presumably, at least for some of us, our first instruction in right or wrong came well before our first instruction in theology. We heard (probably quite loudly) "Don't pull mommy's hair!" before we heard (probably quite softly) "Our Father, who art in heaven." It would seem then that right judgment about what is to be done does not seem to require belief in God.
But the discussion at hand, "Ethics without God," is not about what Thomas calls synesis, a habit of judgment in practical individual cases, an almost purely practical knowledge for right living.{2} This sort of knowledge is almost entirely practical, distinguished from reason in action (prudence) merely as the final judgment about what is to be done differs from executing the judgment. Ethics is practical knowledge, but of a more theoretical nature. Ethics is not purely theoretical knowledge, of course, but knowledge of an operable object, how human actions are to be ordered rightly. This operable object is, in ethics, considered theoretically and not for immediate execution in action. In moral philosophy, we seek a theory of practice. Ethical knowledge, as developed in moral philosophy, is not immediately in the process of being enacted. There is therefore a gap between a right theory of practice and right practice itself. Thus, although moral philosophy is undertaken to direct action, it is nevertheless possible to have right judgment about what to do here and now (synesis) and correct purely practical ethical knowledge (prudentia) and lack a theory of practice, and conversely one can have a right theory of practice but lack right purely practical knowledge as the person with weakness of will makes evident. A saint can flunk a course in moral philosophy; a professor of moral philosophy can fail to be saintly.
It seems evident that one could have synesis without knowledge of God, for in a good society almost everyone would instinctively know the wrongfulness of certain kinds of activity, independently of divine instruction or rigorous philosophical education. So I understand the question of "ethics without God" to be asking the following: Is it possible to have moral philosophy, an account of imperfect happiness in this life, without relying on God's existence to "make good" or ultimately justify the claims made on behalf of ethics? In one sense, it is absolutely impossible to have an ethics without God. If God is the necessary cause of all things, then one could not have anything whatsoever without God -- water, turtles, suns, and human beings making judgments about human actions included. However, this point concerns the order of being and not the order of knowing. In the order of knowing, contrary to the neo-Platonic epistemological accounts of Anselm and others, Thomas held that we can know things without first knowing God. God is not the first thing known by which other things are known. For human beings, the first things known are known through the senses, and God as an immaterial Being is not known directly through the senses. What we mean to ask when we address the topic of ethics without God is do we need a Gottesbegriff -- a conception of God in order to come to ethical conclusions. Does knowledge of the ethical truth depend upon or is such knowledge logically posterior to knowledge of God?
To narrow the question more, one could ask: could one have a non- theistic Thomistic ethics? Certainly, a non-theological ethics might be reconstructed from the Summa theologiae -- as Wolfgang Kluxen did in his Philosophische Ethik bei Thomas von Aquin. John Finnis makes a similar effort in his book Aquinas: Moral, Political, and Legal Theory. In both works, the conception of ethics presented does not presuppose a belief in God, though it is open to a belief in God. However, it must be said that such reconstructions of the Summa theologiae must ignore a vast majority of the work under consideration. Thomistic ethics as presented in the Summa says much more about grace than natural law, speaks at much greater length about the gifts of the Holy Spirit than about double effect, and the entire beginning of the Secunda Secundae is devoted to virtues which have no natural counterpart -- namely, infused faith, hope, and charity. Despite the importance and value of such works constructing a strictly philosophical ethics from, mainly, the Summa, these efforts do not, and do not intend to, reflect all of what Thomas actually said about the moral life in his great summary of theology. Of course, nothing is wrong with developing Thomistic ethics as presented in the Summa in certain ways by way of emphasis, reformulation, or even suppression of certain themes addressed by Thomas, but such reconstructions of necessity do not tell the whole story -- since the whole story for Thomas is deeply and inescapably theological.
Since Thomas's account of perfect happiness is inescapably linked, not so much with mysteries of faith as with preambles of faith, it is inherently theistic, though not inherently based on revelation.{3} If we are searching for a non-theological Thomistic ethics, it might be more fruitful if we turned primarily to the Sententia libri ethicorum, rather than either of the two Summae. Two obstacles would immediately block this approach. The first is that the Sententia libri ethicorum is sometimes said to be merely a commentary. If the Sententia libri ethicorum is merely preparatory notes to writing the Summa and/or merely Thomas's reading of the Ethics but no more, then of course to understanding this commentary as expressing Aquinas's views various matters would be deeply mistaken. Without retracing the arguments discussed in a previous Summer Thomistic Institute, I believe this view is not very plausible.{4} Even if this view were true, then the discussion here would simply be about the role of the divine in Thomas's understanding of Aristotle -- a worthy topic of discussion in itself.
Another obstacle would be the view that this commentary is itself a theological and not a philosophical work. Famously Harry Jaffa impuned the reliability of Thomas Aquinas's Sententia libri ethicorum by saying that the commentary imported "six principles of Christian ethics" foreign to Aristotle into the interpretation of the Nicomachean Ethics. If the Commentary on the Ethics is itself a work of Christian moral thought, then the search for a non-theistic ethics cannot begin there. On the face of it, it is quite implausible to hold that the Sententia libri ethicorum is a book of Christian ethics, since the commentary makes no mention of the Trinity, the death and resurrection of Christ, or the sacraments. The Sententia libri ethicorum does not invoke explicitly either the Old or the New Testament. Nothing is said about the Beatitudes, the parables of Jesus, or the exhortations of St. Paul. Indeed, it is hard to imagine an account of Christian ethics in which the name Jesus Christ does not appear a single time.
Jaffa's complaint might be more accurately described as being that Thomas introduced theological beliefs into the commentary, namely belief in divine providence, belief that perfect happiness is impossible in this life, belief in the necessity of personal immortality to complete the happiness intended, apparently by nature, belief in personal immortality, belief in the special creation of individual souls, and belief in a divinely implanted "natural" habit of the moral virtues. These beliefs are not specifically Christian since they are shared by many non-Christians including Jews, Muslims, and other theists. Furthermore not all these beliefs are shared by Christians, since some Protestants reject belief in natural law, a divinely implanted natural habit of the moral virtues. But if we revise Jaffa's complaint from an importing of Christian principles to an importing of theistic principles, what should be said in this case? Recently James C. Doig in his book, Aquinas's Philosophical Commentary on the Ethics: A Historical Perspective, provides a detailed response to the specifics of Jaffa's critique arguing that each of these beliefs, though also revealed, is given a philosophical foundation by Thomas.{5} For example, although God's providence is a matter of revelation, it can also be established as true according to Thomas on the basis of reason. Since I think Doig's argument convincing, I will leave aside the specifics of Jaffa's view and assume that the Commentary on the Ethics is not, at least in any strong sense, a theological work but is rather a philosophical work.
Even if the commentary is in a stronger sense theological, it still may be fruitful to explore the place of God within it.
What specifically does Thomas say about God in the Sententia libri ethicorum? Actually a great deal, including the following: God is the ultimate source of all being{6} and good{7} in whom the truth is first and chiefly found.{8} Not only does God not desire evil,{9} but also God's substance contains no evil whatsoever.{10} God is the principal cause of our happiness.{11} Aquinas remarks that God's power does not extend to contradictions,{12} that the divine nature is simple and unchangeable,{13} and that the existence and the essence of God are identical.{14} Possessing goodness perfectly in himself,{15} the Divine Being provides providential care for human affairs,{16} acts through the contemplation of truth, and confers the greatest blessings on those who love and honor their intellect.{17} Indeed, the Commentary on the Ethics frequently mentions of God. The Sententia libri ethicorum makes more than 180 references to God, the First Mover, or the divine.
However, word counts do not reveal the importance, centrality, or role of the God, the First Mover, or the Divine in the commentary. Thomas also makes frequent mention of ancient persons of fame such as Homer, Pericles, and Trojan, but the Sententia as an account of ethics hardly depends on belief in or the existence of such personages. The role the divine plays in the Sententia libri ethicorum cannot be determined simply by counting citations, nor would this role be properly understood properly through a quick summary of what Thomas says about God as given above. Most references to the divine in the Commentary are asides, said almost in passing to exclude some possible error or to expand on a fairly tangential point. For instance the Aristotelian text in many places speaks of the "gods," and in commenting on such passages Thomas often reminds readers that Aristotle is referring to separated substances.{18} Although most references to the divine play only a tangential role, some references to God play important roles in the argument, and it is these passages that I would like to examine at greater length.
The discussion will have two main parts. First, I will examine a passage which indicates that knowledge of God does not play an important role in ethics according to Thomas's understanding of the Ethics. Next, I will bring forward a number of passages in which God does appear to play a central role, but show why the wider argument presented in the Sententia libri ethicorum does not depend on such passages. I hope that an examination of both these kinds of passages will make more clear the role the divine plays in Thomas's commentary. And here I come to my thesis: although the moral life as presented in this work is definitely compatible with belief in God, and in fact does appeal to God in a substantive way, nevertheless theistic belief is not a necessary component or required prerequisite for the account of the moral life presented in the Sententia libri ethicorum.
Against his friends the Platonists who sought to show that ethical knowledge was derived from metaphysical knowledge, Aristotle rejected this idea. Unlike Socrates, for Aristotle one does not need to know about the separated "Form" of the Good in order to have ethical knowledge of the morally good. Thomas's argument for this conclusion begins with a reminder of the scope of moral philosophy. As Thomas remarks in the commentary on the first book of the Ethics, in moral philosophy, we seek the end that is happiness as able to be secured through human actions. He writes:
We are looking for the happiness that is the end of human acts. The end, however, of man is either some thing he does or some external thing. This can be the end of man either because it is produced, as a house is the end of building or it is possessed as a thing that is used.{19}
The end of human acts could be then one of three things. First, the end could be something an agent does, such as singing, thinking, or moving. Secondly, the end could be something an agent makes, such as a house, a boat, or a diagram. Thirdly, the end could be something an agent possesses or uses, such as looking at the beauty of the Swiss Alps or the 'Romantic Rhine' on a clear spring day. Such objects of natural beauty are not themselves human actions nor are they human artifacts but a human being may enjoy them, and in that sense use or possess them and so derive happiness. But human happiness as achievable by human action (finis quo) does not involve God as any of these three kinds of ends, since God, as a separated good, is not a human action, a human fabrication, or an object of human enjoyment. God is not a human action like human thinking or human desiring. Contra Feurbach and worshipers of idols, God is not a human creation or fabrication. Finally, God according to Thomas in the Commentary is not an object that could be possessed or enjoyed by human beings in this life. "Moreover, it (this separated good) does not seem to be something possessed by man as he possesses things used in this life. Obviously, then, the common or separated good is not the good of man that is the object of our present search."{20} God cannot be possessed in this life but only enjoyed in the life to come. So the separated good, God or any other, cannot be the end that is sought in the moral life as accounted for in moral philosophy.
Now I would like to examine passages where belief in God plays a substantive role in the argument. The first place the divine plays a pivotal role in Thomas's argument is in his discussion of whether there is a final end for human beings. There must be a final end, since we cannot proceed to infinity in desired ends because then our desires would never be able to reach fulfillment. Natural desires cannot be in vain, so there must be some final end for human beings. Now, someone might ask, why couldn't natural desires be in vain? Thomas answers: "But this is impossible. The reason is that a natural desire is nothing else but an inclination belonging to things by disposition of the First Mover, and thus cannot be frustrated. Therefore it is impossible that we should proceed to an infinity of ends."{21} Natural desire cannot be in vain for it belongs to a creature by virtue of the First Mover. About the final end of human beings Thomas makes a similar argument elsewhere. Thomas writes: "It may happen that a man is a weaver, tanner, grammarian, musician, or anything else of the kind. In none of these capacities does he lack a proper operation, for otherwise he would possess them as empty and useless things. Now it is far more unfitting that a thing ordained by divine reason, as is the naturally existent, should be unprofitable and useless than a thing arranged by human reason. Since, therefore, man is a being possessing a natural existence, it is impossible that he should be by nature without a purpose, or a proper operation."{22} So here we find the divine invoked in order to support the idea that man has a proper operation. Without a proper operation and a natural end, then man's desires would be in vain including the desire for happiness which is the basis for a eudemonistic ethics. Thus the Ethics of Aristotle, at least as interpreted by Thomas, depends upon belief in God.
But it should be noted that although Thomas does invoke the divine at this point, he also invokes another argument to reach the same conclusion, and this argument makes no reference whatsoever to God. Aquinas writes that Aristotle: "proves the same truth by means of human members. We must consider that the same mode of operation is found in the whole and in the parts of man, because, as the soul is the act of the whole body, so certain powers of the soul are acts of certain parts of the body, as sight is of the eye. But each part of man has a proper operation; for example, the operation of the eye is seeing; and of the hand, touching; and of the feet, walking; and so of the other parts. We conclude, therefore, that some operation proper to man as a whole exists."{23} If the individual parts of a human being have various functions in virtue of the power of the soul, the soul's power being manifest in both the parts of the body and the soul, then the human being as a whole too must have a proper operation. The conclusion therefore that human beings have a proper operation does not depend on belief in God's existence since it can also be derived in a way that does not rely on a belief in God's existence.
Secondly, the divine enters the Sententia libri ethicorum in a significant way in Thomas's comparison of the intellectual and practical virtues.{24} In arguing for the superiority of the intellectual virtues (and hence the life of contemplation) over the moral virtues (and hence the political life), Thomas appeals to God's nature, as well as the nature of separated substances, as freed from all passions. Almost Anselmian in inspiration, in order to know which life and which virtues are greater than others, he appeals to that than which nothing greater can be conceived. The superiority of a given virtue is seen by its greater resemblance to God. Since God undergoes no passions, God has no need of the moral virtues. God however does enjoy the intellectual virtues such as wisdom. So the intellectual virtues must be better than the moral virtues since the best being has one kind of virtue but not the other. So in order to know about the superiority of the intellectual virtues over the moral, one must have knowledge of the divine.
Once again although God plays a central role in this argument from the Commentary, Thomas provides other non-theistic arguments for the same conclusion. Having established earlier that happiness is activity in accordance with the highest virtue,{25} Thomas understands Aristotle to give a series of arguments that the activity according to the highest virtue is contemplation. None of these depends upon a belief in God, and Thomas spends lectio ten of book ten treating these arguments. First, the highest operation of the intellect is best thing in us. We differ from the beasts not in using reason for practical affairs such as seeking food but in using reason for theoretical aims such as knowing the truth about that which lies beyond the senses. Exercise of the intellect is also most continuous since bodily activity, particularly strenuous bodily activity, rather quickly makes a human being tire. Third, intellectual pleasure, unlike bodily pleasure, does not depend on a previous privation or lack and so is a more "pure" pleasure as opposed to pleasures which depend upon prior pains. Though best pursued with friends, intellectual activity is highly self-sufficient unlike for instance the exercise of justice which requires another person. Although practical virtues may also be means to another end (as temperance helps one finish one's work or justice helps establish peace among neighbors), contemplation is loved for its own sake, not as a means to further ends. Thus, it more especially shares in the nature of happiness as a final end. Finally, unlike the business of a person exercising practical virtue, contemplation pertains to leisureliness, a freedom from labor which is assigned to happy person. Since none of these arguments depends upon belief in God, Thomas can establish the superiority of the exercise of contemplation over moral virtues without relying on the divine even though he does invoke the divine in order to show the superiority of intellectual over practical virtues.
A third way that God would seem to be presupposed for ethics concerns the pedagogy of philosophy. Interestingly, this pedagogy would appear at first glance to support the idea that God is not needed for ethics but things are more complicated than the first glance would indicate. Thomas, following Aristotle, holds that there is a proper order of whereby students master certain subjects first before advancing to more difficult subjects. There is an order to learning in which the necessary prerequisites for understanding more difficult subjects are first mastered in subjects more easily understood.
Therefore, the proper order of learning is that boys first be instructed in things pertaining to logic because logic teaches the method of the whole of philosophy. Next, they should be instructed in mathematics, which does not need experience and does not exceed the imagination. Third in natural sciences, which, even though they not exceeding sense and imagination, nevertheless require experience. Fourth, in the moral sciences, which require experience and a soul free from passions, as was noted in the first book. Fifth, in the sapiential and divine sciences, which exceed imagination and require a sharp mind.{26}
Those subjects that require very little experience are the first that should be learned such as logic and mathematics. Subjects requiring the most experience to master should only be undertaken later, such as the natural sciences. Before the sapiential and divine sciences, moral philosophy should be studied. And the last subject that should be studied is metaphysics. Ethics comes in the middle, after logic and mathematics but before metaphysics, and therefore before a philosophical or metaphysical knowledge of God. So, knowledge of God, at least as acquired in metaphysics should be acquired only after the study of ethics. This Aristotelian-Thomistic pedagogy leads to the conclusion that knowledge of God is not logically prior to ethical knowledge.
But a big problem arises for this line of argument. In the Physics commentary, an exploration pertaining to natural science, Thomas establishes the existence of the unmoved mover, so the existence of God would be something learned before ethics. So even though the divine and sapiential sciences are explored in greatest depth in metaphysics, undertaken after moral philosophy, God's existence is established in the discipline of natural sciences, which should be undertaken before moral philosophy. So the student who follows Aristotle's recommended pedagogy would have knowledge of God before studying the subject of moral philosophy. God is necessary for moral philosophy.
This objection however is not fatal to the position defended here. It doesn't follow from the fact that something is learned before in a particular science that this what is learned is necessary for the following sciences. We also learn in natural philosophy about the characteristics of animals but these facts are not necessary for moral philosophy. We learn the truths of geometry, but it does not follow that the truths of moral philosophy depend upon the truths of geometry. The Aristotelian ordering of learning proves neither that God is needed for moral philosophy (nor does it show that God is not needed).
Finally the divine enters the Commentary in an important way in the consideration of the cause of human happiness. Thomas comments that: "it is tolerable to say that happiness (felicitas) is from a human cause, even if principally from a divine cause, nevertheless in this man must in some way cooperate.{27} In book one, lectio fourteen, Thomas considers the cause of human happiness and rejects fortune as the cause. Rather, happiness is caused proximately by human act but principally and first by a divine cause.{28} So God would seem to be an essential part of eudemonistic ethics as its first and primary cause.
Even though the first and principle cause of human happiness is God but its proximate cause is human. That God would be the first cause of human happiness is rather obvious, since God is the first cause of all things, including the objects of geometry. But this indicates why knowledge of God is not necessarily essential to moral philosophy as understood by Thomas. If God causes all being, then we couldn't exist without God, and if we did not exist we could not perform human actions, the concern of moral philosophy. But moral philosophy need not give an account of all the conditions necessary for the existence of human action, since then moral philosophy would also have to give an account of how our brain stem operates since we cannot perform human action without a functioning brain stem. But surely brain stems are not a facet of moral philosophy despite being a necessary condition for any earthly human action. So too, knowledge of God as first cause is not essential to moral philosophy simply on account of God's existence being necessary for human action. Just as one can understand geometry without knowledge of God so too one can understand Aristotelian moral philosophy without a knowledge of God, even though in terms of the order of being neither geometry nor human actions, the subject of moral philosophy, are possible without God. In the order of knowing, neither geometry nor ethics do depend upon God; although in the order of being, both geometry and ethics depend upon God. Obviously to have a comprehensive knowledge of all things one would have to know the cause of all things, but such knowledge goes well beyond that which is required for ethics. So the fact that Thomas acknowledges that happiness is caused principally and first by a divine cause does not imply that this divine cause must be known or invoked in moral philosophy which seeks to understand the proximate human cause of happiness.
Another way to approach the question about God and happiness in the Sententia libri ethicorum is to note that Thomas seeks to understand happiness in terms of the finis quo the proximate cause by which a person achieves happiness and not primarily in terms of the finis cuius that in which the person finds happiness. The finis quo of the miser is possessing money; the finis cuius of the miser is the money itself.{29} The finis quo of the intemperate person is to enjoy bodily pleasure beyond what is reasonable; the finis cuius is the wine, sex, or food from which the agent derives bodily pleasure. In the Sententia libri ethicorum, Thomas is primarily exploring those actions by which a human person can achieve happiness, the finis quo, and this finis quo does not consist, as noted earlier, in the enjoyment of as separated good such as God. "Moreover, it (this separated good) does not seem to be something possessed by man as he possesses things used in this life. Obviously, then, the common or separated good is not the good of man that is the object of our present search."{30} As he makes clear in the preface, as well as within in the text itself, happiness as the proper operation of a human person (actio humana, finis quo) is the subject of the Commentary on the Nicomachean Ethics.{31}
But this response merely raises another difficulty. Even if happiness understood as a finis quo that is as an operation of a human person, is a created and not an uncreated entity, nevertheless happiness as a finis cuius might consists in an uncreated Being, God. Even if happiness considered as a human operation consists in contemplation, a human action, this contemplation must be contemplation of the highest thing, namely God. So if happiness consists in the contemplation of the highest object by the highest human power, then human happiness at least in terms of the finis cuius cannot be understood without God. So God does enter into his account of the Ethics in a very significant way, namely as the final end (finis cuius) of all rightly ordered human action. But does Thomas actually say this in the Commentary?
One passage in the Sententia affirms the role of the divine in contemplation. In it, Thomas clarifies more explicitly the nature of the finis cuius, the highest objects of contemplation. "the highest of human activities is contemplation of truth; and this is evident from the two reasons by which we judge the excellence of activity. First, on the part of the faculty that is the principle of the activity. Thus this activity is obviously the highest, as the intellect is the best element in us. Second, on the part of the object determining the species of the activity. Here too this activity is highest because, among the objects that can be known, the supersensible -- especially divine objects -- are the highest. And so it is in the contemplation of these objects that the perfect happiness of man consists."{32} The finis cuius of human happiness is the intelligibilia, et praecipue divina. It is important to note the plurality of the objects of perfect happiness in the Commentary. Indeed, this passage, at least for the monotheist, would seem to prove too much in terms of the role of the divine, for the object of contemplation is not the one true God, but rather intelligible objects, and especially divine things. So God does not enter into the finis quo of human happiness, nor is God the sole object of happiness in terms of the finis cuius.
So in conclusion let us return to the question of the paper, perhaps the primary question of our conference: can we be good without God? If we are to have perfect happiness and still our restless hearts, the answer is no. If we are to have an account of perfect happiness as undertaken in moral theology, the answer is again no. But does one always need to know about God's existence in order to come to right practical judgment (synesis) about what is evil to do and what is good? It seems that since our judgment about these things could be derived from non-theistic sources, including syndersis or instruction by others, acknowledging God's existence does not appear to be necessary.
If we are seeking to theoretically understand how to pursue happiness in this life, as it is possible to achieve through virtuous human actions, then if the account of ethics depicted in the Sententia libri ethicorum is correct then again we can be good without believing in God. Although the Divine Being is frequently mentioned by Thomas in the Sententia libri ethicorum, the commentary makes clear that knowledge of this separated Good is not necessary for ethics. In several places where God does play a central role in the Commentary, Thomas establishes the same conclusions via non-theistic arguments as well. Thus, both an atheist and a theist could in principle agree that the Nicomachean Ethics, as understood by Thomas Aquinas, provides a rational account of the ethical life: we can be good without God.
{1} ST II-II, 2, 8, ad 1.
{2} See Sententia Libri Ethicorum Book 6, lect 9, Spiazzi numbers 1235-1256, abbreviated citation form SLE 6.9.1235-1256. Throughout the Latin passages come from the version of the Sententia found in the Index Thomisticus, the English translation is by C.I. Litzinger.
{3} ST II-II, 2, 8, ad 1.
{4} See (hopefully) Christopher Kaczor, "Thomas Aquinas's Commentary on the Ethics: Merely an Interpretation of Aristotle?" submitted to the American Catholic Philosophical Quarterly.
{5} James Doig, Aquinas's Philosophical Commentary on the Ethics: A Historical Perspective. (London: Kluwer Academic Press, 2001) chapter four.
{6} SLE 5.2.1139
{7} SLE 1.18.223, SLE 1.2.30, SLE 1.18.223.
{8} SLE 1.6. 77.
{9} SLE 10.12.2122.
{10} SLE 1.6.81, SLE 1.9.115.
{11} SLE 1.14.169.
{12} SLE 6.2.1139.
{13} SLE 7.14.1535.
{14} SLE 9.4.1807.
{15} SLE 9.4.1807.
{16} SLE 10.13.2133.
{17} SLE 10.14.2138.
{18} SLE 1.18.218.
{19} SLE 1.2.21.
{20} SLE 1.8.98.
{21} SLE I.2.21.
{22} SLE I.10.121.
{23} SLE I.10.122.
{24} SLE 10.12.2121-2123.
{25} SLE 10.9.2078.
{26} SLE 6.7.1121.
{27} ostendit tolerabiliter dici quod felicitas sit ex causa humana, quia, etiam si sit a deo principaliter, tamen adhuc homo aliquid cooperatur. SLE 1.14.169. Thomas uses felicitas to denote imperfect happiness in the Commentary and reserves beatitudo for what he calls 'perfect happiness' in the Summa. Beatitudo is but rarely mentioned in the SLE which focuses on felicitas.
{28} felicitas igitur non est a fortuna, sed ab aliqua causa humana proxima, a causa autem divina principaliter et primo. SLE 1.14.179.
{29} ST I-II, 1, 8.
{30} SLE I.8.98.
{31} si autem aliqua res exterior dicatur esse finis, hoc non erit nisi mediante operatione, per quam scilicet homo ad rem illam attingit vel faciendo, sicut aedificator domum, aut utitur seu fruitur ea. et sic relinquitur quod finale bonum cuiuslibet rei in eius operatione sit requirendum. si igitur hominis est aliqua operatio propria, necesse est, quod in eius operatione propria consistat finale bonum ipsius, quod est felicitas, et ita genus felicitatis est propria operatio hominis. si autem dicatur in aliquo alio felicitas consistere, aut hoc erit aliquid quo homo redditur idoneus ad huiusmodi operationem, aut erit aliquid ad quod per suam operationem attingit, sicut deus dicitur esse beatitudo hominis. SLE 1.10.119-120.
{32} optima autem inter operationes humanas est speculatio veritatis. et hoc patet ex duobus, ex quibus pensatur dignitas operationis. uno modo ex parte potentiae, quae est operationis principium. et sic patet hanc operationem esse optimam, sicut et intellectus est optimum eorum quae in nobis sunt, ut prius ostensum est . . . alio modo ex parte obiecti, quod dat speciem operationi. et secundum hoc etiam haec operatio est optima; quia inter omnia cognoscibilia optima sunt intelligibilia, et praecipue divina. et sic in eorum speculatione consistit perfecta humana felicitas. SLE I0.10.2087.