Various Aspects of the Epistemological Problem

The Philosophical System of Thomas Aquinas, by Maurice de Wulf, edited and adapted for the web by Jonathan Dolhenty

IV. Various Aspects of the Epistemological Problem

A. Metaphysical and psychological aspects

The Schoolmen of the thirteenth century never doubted for a moment that our faculties of knowing are capable of attaining extra-mental reality. In those dogmatic days there were no critics and adversaries such as those of later times, for whom the critical problem of knowledge occupies so large a place in philosophical speculation.

In the writings of Thomas Aquinas, and especially in the fine treatise concerning Truth (De Veritate), the problem of truth is considered from two distinct points of view. The first is metaphysical; the second psychological and critical.

The metaphysical doctrine sets out from the study of God, the infinitely perfect Being, whose existence is here presupposed, and continues in a long series of magnificent synthetic conceptions, — a chain of gold, as it were, of which the first links were forged by Plato, others by St. Augustine, and the last by Thomas himself. Here is the chain of reasoning in its logical sequence.

God is Infinite.
He alone possesses the plenitude of reality (XI).
Every possible being (which will necessarily be outside of an distinct from Him) must possess its ratio aeterna, eternal reason, or explanation, in the Infinite Essence of God [1]. In other words, every finite being is a feeble and distant imitation of the Divine Infinity.
There is no limit to the multitude of such possible beings.
God, in knowing Himself, knows by means of the same intuitive vision all possible things, whether He calls them to existence, or not.
Man, with his Intelligence, occupies a certain rank in this hierarchy of essences.
In consequence, human nature or essence (that which each man is) stands in a certain fixed relation to the Infinite Being.
Likewise, the human mind is a torch which has been lit by the Sun of Truth, i.e., the Divine Being, in order to reveal beings and reality, just as fire is made to burn.
Thus, in the last analysis, God is the foundation of the reality and of the intelligibility of all that exists or is possible on the one hand, and of the aptitude of the human mind to attain to reality, i.e., to possess truth, on the other.
A conception like this results from a coordination of many theories presupposed here and established elsewhere, and forms a good example of the cohesion of scholastic philosophy as a whole (XIX, B). The psychological aspect of the problem of truth is quite different. It rests upon the analysis of the facts of consciousness.

B. The data of the epistemological problem

The treatise De Veritate sets out quite clearly the data of the epistemological problem of certitude and truth.

(a) It reduces it to a reflective examination of those beliefs which we form spontaneously and which we find already in our minds, when we start our reflection.
(b) It regards truth as an attribute of the judgment, and not of the concept or of the simple apprehension.
(c) From the validity of judgments which are the results of reflection, it deduces that of spontaneous judgments which we formulate almost unconsciously.
Let us examine these points more closely.

(a) The epistemological inquiry consists of an examination of preexisting beliefs by means of reflection. We are dogmatists from birth. As a result of the influence of education, our domestic and social surroundings, and also the spontaneous play of our faculties, we firmly assert to a great number of propositions which have entered into our minds with question or examination, like a crowd entering a free place of amusement. For instance, we believe

that 2 + 2 + 4;
that our relatives exist;
that there are things we ought to do and others which we ought not to do, etc.
Spontaneous and direct certitude precedes therefore the inquiry into certitude. Nay more: it is the former that is the object studied by the latter. Without spontaneous assertions, the epistemological inquiry would be void and empty. The critical or epistemological problem consists of scrutinizing these beliefs one by one, just as we separate the good grain from the chaff. We then examine the motive which leads us to eliminate some and keep others. “This investigation,” writes Thomas, “consists in taking as the object of our inquiry, not only our subjective act of assent, but also the data to which we assent” [2].

(b) The process is an examination of the judgment, because truth is an attribute of judgment, and not of simple apprehension.

This is a doctrine which no Schoolman ever opposed. The idea of God, man, oak tree is neither true nor false, any more than the beings themselves which we call God, man, oak tree, are strictly speaking true or false. The reason for this is that truth consists in a relation of agreement or conformity, — adequatio. Now in that which is simple — such as an idea — there is no place for a relation [3]. The agreement or conformity of the content of an idea, such as good, living, derived from an acorn, with a being to which we refer it, exists only in, and by the judgment. Examples: ‘God is good,’ ‘man is a living being,’ ‘the oak tree originates from an acorn.’ Truth therefore in its strict sense belongs to the judgment [4], and it is found in simple apprehension, or in the things themselves, only in a sense which is secondary, and rests upon the first.

(c) The examination by way of reflection enables us to test the value of those judgments which we form spontaneously, before and without the aid of reflection. There is no fundamental difference between the mental process in the case of primordial and direct assertions and that in the case of controlled or reflective assertions. But the only means we possess of examining the value of the former is to study them through the prism as it were of the latter. We shall find later that it is reflection which gives us the motive and criterion for retaining some of our spontaneous assents and rejecting others. It is also reflection which justifies our belief that judgments recognized as true attain to the external world in a way which is indeed inadequate, but yet relevant. We shall thus be enabled to draw the conclusion that the external reality is in the last analysis responsible for our spontaneous assertions subsequently recognized as valid, and that accordingly, the human mind is capable of attaining to truth: its nature is to be in conformity with things. By reflective examination and reasoning, we recognize that our original mental operation is a valid and reliable one.

The two mental processes of which we have been speaking — the reflective examination of our assertions, and the direct acquisition of judgments to which we assent without any conscious motive for doing so — are clearly referred to by Aquinas, but he does not always keep the two quite distinct. He passes continually from the point of view of direct knowledge to that of reflection, and vice versa [5].



  1. This is the theory of St. Augustine. The doctrine of the rationes aeternae or eternal reasons of things, is a modification of the Ideas of Plato, which begins to appear in the writings of the later Stoics.

  2. De Veritate, q. 1, art. 9.

  3. Contra Gentiles, I, cap. 59.

  4. De Veritate, q. 1, art. 3.

  5. To my mind, this explains the differences amongst the interpreters of the texts of Aquinas concerning the notion of truth. Interminable discussions have been waged recently on this subject.

The late Dr. Jonathan Dolhenty was the Founder and President of The Center for Applied Philosophy and the Radical Academy, and is Honorary Philosophy Editor at The Moral Liberal. The Moral Liberal has adopted these projects beginning with a republishing and preserving of all of Dr. Dolhenty’s work.