It is evident from the discussion of the general principles of knowledge, and especially the process of intellectual knowledge, that the question of validity is practically taken for granted in the system of our author; it is an undercurrent directing and determining the statements and developments of knowledge in its various stages as set forth by Aquinas in detail. The reality of the object, of the external world, is rooted in the fundamental statements of knowledge thus far expressed. The union of subject and object, the manner in which the object is present to the knower, the intellectual process that gives birth to the intelligible in sensible objects, all look to something extra animam -- "the act of knowledge extends itself to those things which are outside the knower, for we also know those things which are external to us."{1} According to Gardair, "St. Thomas seems to regard as indubitable the prime veracity of the senses rather than to demonstrate it."{2} Parges is in accord with this view. "The great Doctors of the Middle Ages believed in the immediate perception of bodies by the external senses as a primitive fact clearly attested by the consciousness of each man."{3} These statements become general when we recall that for Aquinas all knowledge takes its rise in the senses, according to the axiom: Nihil est in intellectu quod prius non fuerit in sensu.{4}
A few sentences will suffice to confirm the above view. First, as regards the senses. "The sense is a certain passive power capable of being changed by an external sensible object."{5} "The sense always apprehends the the thing as it is, except there be an impediment in the organ or in the medium."{6} Because "sensible objects exist actually outside the soul,"{7} there is no need of an active sense corresponding to the active intellect. We have seen that all knowledge is by species and that the species is only the means of knowledge; what is primarily and immediately and actually known is the object the species represents. Moreover, both powers of cognition -- sense and intellect -- are passive and must be acted upon by the objects, to which they add nothing and from which they take nothing, before there is knowledge. This double phase of activity and passivity in knowledge, presupposes external reality. This is expressed in a statement of A. Seth: "Knowledge is an activity, an activo-passive experience of the subject, whereby it becomes aware of what is not itself."{8}
We need say little about the reality contained in intellectual knowledge, for though this knowledge is distinct in kind from sensory, yet it rests on sensitive images as a basis, and the whole process of the active intellect is concerned with extracting the intelligible, the essence, wrapped up in the image, which is the proper object of the intellect. There is a twofold aspect of the operation of knowing in man, one wholly internal and another that has as its terminus "something existing outside him,"{9} an external object. "The first object of the human intellect is not its own essence, but something external, namely, the nature of a material thing. Hence what is primarily known by the intellect is an object of this nature, and secondarily, the act by which the object is known."{10} To multiply quotations would be useless and would largely repeat what was said when speaking of intellectual knowledge.
We can then say we know the object, we know it as something external, and we know it at once. The perception of reality is not the result of an inference as Descartes and many moderns hold, but the idea represents the object at once without any intermediate presentations. But how does the idea make the object known to us? What does it mean? The idea is a state of the mind, and it is also representative of something. In this second, its epistemological aspect, as representative of something, what is its value? Seth admits the twofold aspect of the idea and yet holds: "Immediacy must be given up before any tenable theory of perception and any philosophical doctrine of Realism can be established."{11} St. Thomas maintains that the idea as representation, or, to make the statement general, the species which is the likeness or representation of the thing makes the thing itself known at once. If we hold with Berkeley that an idea can only be like an idea, we are shut off from a knowledge of the real existence of things material. The idea as an idea, as a state in the mind, of course, can only be like another idea, but when we recognize that "knowledge means nothing if it does not mean the relation of two factors, knowledge of an object by a subject,"{12} and "that we are never restricted to our own idea as ideas; from the first dawn of knowledge we treat the subjective excitation as the symbol or revealer to us of a real world,"{13} we see the aspect of the idea that looks toward something other than its presence as a mere mental state. It is only a question of what this something other is. And here we meet the second general principle of knowledge -- the object is known according to the nature of the knower -- from the critical point of view. In the system of St. Thomas the answer to the something other is at hand: the idea represents to the subject some real object that is known immediately by means of the idea, but known according to the nature of the knower. The fact that everything the subject knows he knows according to his nature, renders the objections usually made on the score of incompatibility of the nature of the knowing subject with certain objects that we say we do know, of little or no consequence; for though the intellectual idea as such is wholly immaterial, yet the image from which it has been derived is material, and the idea is simply the image considered in an immaterial way, namely, the essence freed from material conditions.{14}
The real difficulty from the modern point of view is to explain how the species represents the thing in itself since the species is in the knower according to the nature of the knower. Kant admits a relation between the subject and the object, but this relation is based upon an adaptation of the object to the subject, which imposes on the object its forms, categories, or ideas; we know appearances, phenomena only; all knowledge is purely subjective due to internal elements, and hence a real knowledge of the nature of things is excluded, things in themselves cannot be known. For St. Thomas, there is also a relation between the subject and the object, but this relation is based on the natural proportion, though relative, of the object and the subject. This idea of a natural proportion is a fruitful and satisfying one in the system of Aquinas. When we consider that knowledge is a fact, and subject and object are brought in presence of each other in some way, the first natural suggestion seems to be, the subject and the object must be related to each other in a way that will account for this knowledge, there must be a proportion between them that will enable us to resolve their connection if we go to work with the data on hand. It is not a great concession to admit with Dogmatism the reliability of our faculties in the quest of truth, and on this basis to account for the facts we possess; it is, on the contrary, rather difficult to see the wisdom of any other proceeding.
{15} The definition of truth adopted by St. Thomas is familiar -- adaequatio rei et intellectus.{16} Strictly, this adequation is only found in the Divine Mind, for God alone knows things as completely as they are knowable, since their truth depends on His Ideas. Things are measured by the Divine Ideas, whereas our ideas are measured by the things. Hence we simply have a proportional or relative knowledge of them, though it is true as far as it goes.{17} A faculty in normal condition, operating upon reliable data, always leads to truth. Each faculty has a specific portion of reality about which it is especially concerned, and when limited to this sphere it never gives a false report: "if the faculty is present, its judgment about its proper object will never be at fault."{18} In sensitive knowledge the sense is always true when busied with its specific object -- sight in case of color, hearing for sound, and the like, unless it is impeded in its normal action. Moreover, it seizes the object as it is. "The sense always apprehends the thing as it is, unless there is an impediment in the organ or in the medium. The sense is not the dominus of falsity, but the imagination."{19} If there is error, it will be found in the imagination, which puts together the various elements that have come through the senses. The intellect works on this image, which represents an objective reality, and extracts the idea which will also be objective, since it is the deliverance of the image. The intellect can never be deceived about the essence, simply considered as apprehended, for this is its specific object; but error may arise in the further processes of judgment and reasoning, owing to faulty proceeding. "The specific object of the intellect is the essence of a thing. Whence properly speaking, the intellect is never deceived about the quiddity of a thing, but it may be deceived about matters connected with the essence or quiddity while it relates one thing to another by judgment or ratiocination."{20} Truth or error is found, strictly, in the affirmation or negation of the judgment -- in the componendo et dividendo of Aquinas -- and in the reasoning based on these judgments. "In the intellect, truth and falsity are primarily and principally found in the judgment of the one who affirms or denies."{21} The judgment and subsequent reasoning are true and have objective value if not impeded in their normal action, for they rest, through the idea, the image, the sense, on the reality of the object itself.{22} The idea, however, has certain qualities that are not found in the image that gave rise to it. The thing represented by the idea, the essence -- is endowed with conditions of necessity and universality, whereas the image is contingent and particular. Whence does the idea derive these attributes? Are they given in the representation of the object or are they simply due to the intelligence itself operating on the object, impressing a part of its substance on the object? This recalls the Controversy about the Universals, and the Critical Theory of Kant. The position of St. Thomas -- that of Moderate Realism -- is well known. For him, the universal did not exist separate from the object as Plato held, nor was it simply a name with no corresponding reality as Nominalism maintained, but it was the result of mind and object. It existed in the mind but had its basis in the thing. "There is a threefold diversity of objects signified by names. There are some which, according to their whole being, complete in themselves, are extra animam, as man, stone. There some that have no extra-mental existence, as dreams and chimerical images. There are some that have a fundamentum in re extra animam, but their formal completion is due to mental activity, as is the case with the universal." The universal is the result of the action of the mind, but it has its basis in the object. "Humanity is something in re, yet as there found it is not the formal concept of the universal, since extra animam there is no humanity common to many . . . I say the same of truth, because it has a fundamentum in re, but its concept is completed through the action of the intellect when, namely, it is apprehended in the manner in which it is."{23} The active intellect abstracts the universal from the mental image and gives it the final character of universality which existed but in germ, in potency, in the singular, contingent image. "It is the theory of the Active Intellect which solves the question so often agitated by modern philosophers: Whence comes it that the laws of reason accord with the laws of nature."{24} The thought contained in the idea results from the presence of the image acted upon by the intellect, the image is the outcome of the deliverance of the sense, which in turn connects with external reality. So fundamentally, the external object is found in the highest operation of the intellect, for we can trace the object through the various stages that lead to the final act, and nowhere along the line of development are we made aware of any elements that come from a source other than the presence of the object in relation to the knowing faculty. For Kant, anything that is universal, necessary, is subjective, hence if we apply these qualities to ideas they can only have an internal significance, and do not relate us with objective reality as it is in itself. For St. Thomas, if we begin with the real -- as we do in sensation -- and proceed logically with normal faculties, we end with the real; hence there is reality throughout the whole process of knowledge. We have already noted that all our ideas betray signs of their sensuous origin, for if a sense is wanting or injured the intellectual data that would result from it are absent; moreover, the image is also required when we wish to re-think what we have already thought about or known. This is furthcr emphasized in our knowledge of immaterial beings, as of God; for we can know an object separated from all materiality only by analogy of sensuous things or by notions derived from them.
The consequence of Kant's view on the question of the validity of our knowledge in contrast to that of Aquinas is found in the Relativity of Knowledge advocated by Hamilton and Spencer, and in the position of J. S. Mill, who also allies himself closely with Hume. What then is the extent of our knowledge? How much of reality can we know, and do all men know the same amount?
We know the universal, the essence in the material object, not exhaustively, however, but in a proportionate way; that is, it is known by us in so far as our knowing power will permit us to know it -- for the object is known according to the nature of the knower. Our make-up as man necessitates a connection with matter that renders our knowledge dependent on it to such an extent as to exclude a perfect or complete grasp of the object itself. The thing to be known is the same for all men, but the intellectual state of the knower in the presence of the object depends upon his bodily condition and likewise on the good form of the inferior powers of knowledge -- sense and imagination -- when the object was presented to them.{25} "The higher the intellect the more it knows, either a greater number of objects or at least more reasons for the same objects."{26} Again, "Some men can not grasp an intelligible truth unless it be explained to them part by part . . . others, who have a stronger intellect, can sieze much from few data."{27} All men, however, can know the object really, its essence, by a consideration of its manifestations. This is the important item in all knowledge, God not excepted, for if we can not know HIm from what He manifests of Himself, then truly is knowledge of Him impossible. The causal idea here involved is at the basis of all validity of knowledge; it bears the whole burden of the knowableness of God in the system of St. Thomas, and will be considered at length shortly.
Hamilton justly argues that if we had more means of knowledge, had better faculties, we should know more and better, but his conclusion to absolute relativity of knowledge based on this lack of powers is unwarranted. "But were the number of our faculties coextensive with the modes of being -- had we for each of these thousand modes a separate organ competent to make it known to us, -- still would our whole knowledge be, as it is at present, only of the relative. Of existence absolutely and in itself, we should then be as ignorant as we are now."{28} This position is answered in the statement of Straub: "It is true that we do not attain to all that is or can be in rerum natura, by the senses, but it is one thing to say, what we seem to know in things is really in them, and it is quite another to contend, that we reach, by our knowledge, whatever is present in things."{29}
Spencer's conclusions to the relativity and inconceivability of what we are led to recognize as the legitimate outcome of our reasonings, rests on a misapprehension of the terms used. The statement of J. S. Mill: "Experience therefore affords no evidence, not even analogies, to justify our extending to the apparently immutable a generalization grounded only on our observation of the changeable",{30} is opposed to the view of Aquinas -- "Through the active intellect we know immutable truth from mutable things, and we discern things themselves from their likenesses."{31} True objective reality and the principle of causality give us a reliable knowledge of things and allow us to arrive at an equally valid and non-relative view -- always keeping in mind the limitations of our nature -- of what really transcends the senses, and finally a view of the systematic relation of things. Ladd summarizes his chapter on Knowledge and Reality in these words: "All this amounts to saying that the very existence of our cognitive activities, and of the products which mark their development, whether for the individual or for the race, rests upon the general assumption that things and minds do so causally determine each other as to show that they belong to one system of Reality."{32} Reality in its various relations and interdependencies leads back to one author of all in whom we see the final and complete expression. This will come to light in the portion of the subject we are about to consider, where the principles we have just discussed will give us a knowledge of God, of whom St. Thomas says: "However meagre be our intellectual preception of divine knowledge, this will be more for us, as an ultimate end, than a perfect knowledge of inferior intelligible things."{33}
{1} Actus cognitionis se extendit ad ea quae sunt extra cognoseentem. Cognoscimus enim etiam, ea quae extra nos sunt. Sum Theol., I, q. 84, a. 2.
{2} L'Objectivité de la Sensation, Annales de Phil. Chretienne, 1895, p. 17.
{3} Theorie de la Perception Immediate d'apres Aristote et St. Thomas. Ibid., 1891, p. 441.
{4} It is true to say as Ladd does -- with St. Thomas "the psychological inquiry as to the nature, results, and certainty of its (the intellect) functioning is thus made the most important of epistemological inquiries." But his understanding of this product is inadequate, as his conclusion evidences -- "with such views of the origin of knowledge as the foregoing, the validating of knowledge becomes a hopeless puzzle." Phil. of Knowledge, p. 53 That there is no inconsistency bctween the psychology of knowledge and the epistemology of knowledge as treated by St. Thomas, will be clear, we think, from an exposition of his views. "The theories of validity ought to correspond to the theories of origin: It is thus -- Nominalism, Conceptualism and Realism correspond perfectly to Sensism, Innatism, and Peripateticism. Peillaube, Theorie des Concepts, p 347.
{5} Est autem sensus quaedam potentia passiva, quae nata est immutari ab exteriori sensibili. Sum. Theol., I, q. 78, a. 3.
{6} Sensus semper apprehendit rem ut est, nisi sit impedimentum in organo, vel in medio. De Veri., q. 1, a 11.
{7} Sum. Theol., I, q. 79, a. 3 ad 1.
{8} The Problem of Epistemology, Phil. Review, vol. 1, p. 513.
{9} Sum. Theol., I, q. 14, a. 2.
{10} Nec sui intelligere est objectum primum ipsa ejus essentia. sed aliquid extrinsecum, scilicet natura materialis rei. Et ideo id quod primo cognoscitur ab intellectu humano, est hujusmodi objectum; et secundario cognoscitur ipse actus, quo cognoscitur objectum. Sum. Theol., I, q. 87, a. 3. This statement is exactly the opposite of the view held by Descartes and many modern psychologists, for whom the sensation is the only and the first immediate object of perception.
{11} Loc. cit., p. 515.
{12} A. Seth, loc. cit., p. 513.
{13} A. Seth, Scottish Philosophy, p. 103
{14} Quae (anima) tamen habet duas virtutes cognoscitivas. Unam, quae est actus alicujus corporei organi; et huic connaturale est cognoscere res secundum quod sunt in materia individuali; unde sensus non cognoscit nisi singularia. Alia vero virtus cognoscitiva ejus est intellectus, qui non est actus alicujus organi corporalis. Unde per intellectum connaturale est nobis cognoscere naturas, quae quidem non habent esse nisi in materia individuali rei, non tamen secundum quod sunt in materia individuali, sed secundum quod abstrahuntur ab ea per considerationem intellectus. Sum. Theol., I, q. 14, a. 4. The close connection between the material image and the immaterial idea is here indicated.
{15} To all appearances. the objection so commonly urged against the proceeding of Kant as involving a vicious circle or leading to a contradiction, is well grounded. He seeks to prove that our faculties are incapable of arriving at truth, and in doing so uses the very faculties he has called in question.
{16} Per conformitatem intellectus et rei, veritas definitur. Sum. Theol., I, q. 16, a. 2.
{17} Res naturales, ex quibus intellectus noster scientiam accipit, mensurant intellectum nostrum: sed sunt mensuratae ab intellectu divino, in quo sunt omnia creata, sicut omnia artificiata intellectu artificis. De Veri., q. 1, a. 2. {18} Ad proprium objectum unaquaeque potentia per se ordinatur secundum quod ipsa: quae autem sunt hujusmodi, semper eodem modo se hahent. Unde manente potentia non deficit ejus judicium circa proprium objectum. Sum. Theol., I, q. 85. a. 6.
{19} Sensus semper apprehendit rem ut est, nisi sit impedimentum in organo, vel in medio. Sensus non est dominus falsitatis, sed phantasia. De Veri., q. 1, a. 11.
{20} Objectum autem proprium intellectus est quidditas rei. Unde circa quidditatem per se loquendo intellectus non fallitur, sed circa ea, quae circumstant rei essentiam vel quidditatem, intellectus potest falli, dum unum ordinet ad alterum vel componendo vel etiam ratiocinando. Sum. Theol., I, q. 85, a. 6.
{21} In intellectu autem primo et principaliter inveniuntur falsitas et veritas in judicio componentis et dividentis. De Veri., q. 1, a. 11.
{22} It is not surprising that this conformity or proportion should exist between things and the human mind, when we recall, that, according to Aquinas, God is the author of both. They are the expressions of His Ideas, and in His Mind there is the most complete unity and harmony. "In Deo autem tota plenitudo intellectualis cognitionis continetur in uno." Sum. Theol., I, q. 55, a. 3.
{23} Eorum, quae significantur nominibus, invenitur triplex diversitas. Quaedam enim sunt, quae secundum esse totum completum sunt extra animam, et hujusmodi sunt entia completa, sicut homo, lapis. Quae autem sunt, quae nihil habent extra animam, sicut somnia et imaginatio chimerae. Quaedam autem sunt, quae habent fundamentum in re extra animam; sed complementum rationis eorum, quantum ad id, quod est formale, est per operationem animae, ut patet in universali. Humanitas enim est aliquid in re, non tamen ibi habet rationem universalis cum non sit extra animam aliqua humanitas multis communis. Similiter dico de veritate, quod habet fundamentum in re, sed ratio ejus completur per actionem intellectus, quando scilicet apprehenditur eo modo quo est. Com. on Lomb., I, Dis. 19, q. 5, a. 1.
{24} Piat, L'Intellect Actif, p. 181.
{25} Sum. Theol., I, q. 85, a. 8. There is no separation of mind and matter in the system of Aquinas to the extent of an unbridgable chasm between them. Man is body and soul, and it is man that knows. The aberrations from this view from the time of Descartes are certainly instructive, and speak favorably for the doctrine that avoids all these apparent difficulties -- such as psycho-physical parallelism is busied with -- by interpreting faithfully the facts of consciousness. "If any degradation is suffered by my cognitive faculty in thus being dependent on the causal efficiency of these physico-chemical processes which is called 'my brain states', the remedy for this would seem to be in my not being an animal at all, rather than resorting to a theory which makes a complete breach between my mentality and my animality." Ladd, Phil. of Knowledge, p. 553.
{26} Quanto aliquis intellectus est altior, tanto plura cognoscit, vel secundum rerum multidudinem, vel saltem secundum earumdem rerum plures rationes. C.G., l. 3, c. 56.
{27} Sunt enim quidam qui veritatem intelligibilem capere non possunt, nisi cis particulatim per singula explicatur; et hoc ex debilitate intellectus eorum contingit. Alii vero sunt fortioris intellectus, ex paucis multa capere possunt. Sum. Theol , I, q 55, a. 3. by a consideration of its manifestations. This is the important item in all knowledge, God not excepted, for if we can not know Him from what He manifests of Himself, then truly is knowledge of Him impossible. The causal idea here involved is at the basis of all validity of knowledge; it bears the whole burden of the knowableness of God in the system of St. Thomas, and will be considered at length shortly.
{28} Metaphysics, v. 1, p. 153, lect. 9.
{29} De Objectivitate Cognitionis Humanae, p. 39.
{30} Essays on Religion.
{31} Per quod (lumen intellectus agentis) immutabiliter veritatem in rebus mutabilibus cognoscamus, et discernamus ipsas res a similitudinibus rerum. Sum. Theol., 1, q. 84, a. 6 ad 1.
{32} Loc. cit., p. 554.
{33} C.G., l. 3, c. 25.