The problem of knowledge

The question of knowledge belongs to various sciences, each of which takes a different point of view.Psychology considers knowledge as a mental fact whose elements, conditions, laws and growth are to be determined. It endeavours to discover the behaviour of the mind in knowing, and the development of the cognitive process out of its elements. It supplies the other sciences with the data on which they must work. Among these data are found certain laws of thought which the mind must observe in order to avoid contradiction and to reach consistent knowledge. Formal logic also takes the subjective point of view; it deals with these laws of thought, and neglecting the objective side of knowledge (that is, its materials), studies only the formal elements necessary to consistency and valid proof. At the other extreme, science, physical or metaphysical, postulating the validity of knowledge, or at least leaving this problem out of consideration, studies only the different objects of knowledge, theirnature and properties. As to the crucial questions, the validity of knowledge, its limitations, and therelations between the knowing subject and the known object, these belong to the province ofepistemology.

Knowledge is essentially objective. Such names as the "given" or the "content" of knowledge may be substituted for that of "object", but the plain fact remains that we know something external, which is not formed by, but offered to, the mind. This must not, however, cause us to overlook another fact equally evident. Different minds will frequently take different views of the same object. Moreover, even in the same mind, knowledge undergoes great changes in the course of time; judgments are constantly modified, enlarged or narrowed down, in accordance with newly discovered facts and ascertained truths. Sense-perception is influenced by past processes, associations, contrasts, etc. Inrational knowledge a great diversity of assents is produced by personal dispositions, innate or acquired. In a word, knowledge clearly depends on the mind. Hence the assertion that it is made by the mind alone, that it is conditioned exclusively by the nature of the thinking subject, and that the object of knowledge is in no way outside of the knowing mind. To use Berkeley's words, to be is to be known (esse est percipi). The fact of the dependence of knowledge upon subjective conditionshowever, is far from sufficient to justify this conclusion. Men agree on many propositions, both of theempirical and of the rational order; they differ not so much on objects of knowledge as on objects of opinion, not so much on what they really know as on what they think they know. For two men with normal eyes, the vision of an object, as far as we can ascertain, is sensibly the same. For two men with normal minds, the proposition that the sum of the angles in a triangle equals two right angles has the same meaning, and, both for several minds and for the same mind at different times, theknowledge of that proposition is identical. Owing to associations and differences in mental attitudes, the fringe of consciousness will vary and somewhat modify the total mental state, but the focus ofconsciousness, knowledge itself, will be essentially the same. St. Thomas will not be accused ofidealism, and yet he makes the nature of the mind an essential factor in the act of knowledge:

Cognition is brought about by the presence of the known object in the knowing mind. But the object is in the knower after the fashion of the knower. Hence, for any knower,knowledge is after the fashion of his own nature (Summa theol., I, Q. xii, a. 4).

What is this presence of the object in the subject? Not a physical presence; not even in the form of a picture, a duplicate, or a copy. It cannot be defined by any comparison with the physical world; it issui generis, a cognitive likeness, a species intentionalis.

When knowledge, either of concrete realities or of abstract propositions, is said to consist in the presence of an object in the mind, we cannot mean by this object something external in its absoluteexistence and isolated from the mind, for we cannot think outside of our own thought, and the mindcannot know what is not somehow present in the mind. But this is no sufficient ground for accepting extreme idealism and looking upon knowledge as purely subjective. If the object of an assent or experience cannot be absolute reality, it does not follow that to an assent or experience there is no corresponding reality; and the fact that an object is reached through the conception of it does notjustify the conclusion that the mental conception is the whole of the object's reality. To say thatknowledge is a conscious process is true, but it is only a part of the truth. And from this to infer, withLocke, that, since we can be conscious only of what takes place within ourselves, knowledge is only "conversant with ideas", is to take an exclusively psychological view of the fact which asserts itself primarily as establishing a relation between a mind and an external reality. Knowledge becomes conversant with ideas by a subsequent process, namely by the reflection of the mind upon its own activity. The subjectivist has his eyes wide open to the difficulty of explaining the transition from external reality to the mind, a difficulty which, after all, is but the mystery of consciousness itself. He keeps them obstinately closed to the utter impossibility of explaining the building up by the mind of an external reality out of mere conscious processes. Notwithstanding all theorizing to the contrary, the facts impose themselves that in knowing the mind is not merely active, but also passive; that it must conform, not simply to its own laws but to external reality as well; that it does not create facts andlaws but discovers them; and that the right of truth to recognition persists even when it is actually ignored or violated. The mind, it is true, contributes its share to the knowing process, but, to use the metaphor of St. Augustine, the generation of knowledge requires another cause: "Whatever object weknow is a co-factor in the generation of the knowledge of it. For knowledge is begotten both by theknowing subject and the known object" (De Trinitate, IX, xii). Hence it may be maintained that there are realities distinct from ideas without falling into the absurdity of maintaining that they are known in their absolute existence, that is apart from their relations to the knowing mind. Knowledge isessentially the vital union of both.

It has been said above that knowledge requires experience and thought. The attempt to explainknowledge by experience alone proved a failure, and the favour which Associationism found at first was short-lived. Recent criticism of the sciences has accentuated the fact, which already occupied a central place in scholastic philosophy, that knowledge, even of the physical and mental worlds, implies factors transcending experience. Empiricism fails completely in its endeavour to explain and justifyuniversal knowledge, the knowledge of uniform laws under which facts are brought to unity. Withoutrational additions, the perception of what is or has been can never give the knowledge of what will certainly and necessarily be. True as this is of the natural sciences, it is still more evident in abstract and rational sciences like mathematics. Hence we are led back to the old Aristotelean and Scholasticview, that all knowledge begins with concrete experience, but requires other factors, not given in experience, in order to reach its perfection. It needs reason interpreting the data of observation, abstracting the contents of experience from the conditions which individualize them in space andtime, removing, as it were, the outer envelope of the concrete, and going to the core of reality. Thusknowledge is not, as in Kantian criticism, a synthesis of two elements, one external, the other depending only on the nature of the mind; not the filling up of empty shells—a priori mental forms orcategories—with the unknown and unknowable reality. Even abstract knowledge reveals reality, although its object cannot exist outside of the mind without conditions of which the mind in the act ofknowing divests it.

Knowledge is necessarily proportioned or relative to the capacity of the mind and the manifestations of the object. Not all men have the same keenness of vision or hearing, or the same intellectualaptitudes. Nor is the same reality equally bright from all angles from which it may be viewed. Moreover, better eyes than human might perceive rays beyond the red and the violet of the spectrum; higher intellects might unravel many mysteries of nature, know more and better, with greater facility, certainty, and clearness. The fact that we do not know everything, and that all ourknowledge is inadequate, does not invalidate the knowledge which we possess, any more than the horizon which bounds our view prevents us from perceiving more or less distinctly the various objects within its limits. Reality manifests itself to the mind in different ways and with varying degrees of clearness. Some objects are bright in themselves and are perceived immediately. Others are known indirectly by throwing on them light borrowed elsewhere, by showing by way of causality, similarity,analogy their connection with what we already know. This is essentially the condition of scientificprogress, to find connections between various objects, to proceed from the known to the unknown. As we recede from the self-evident, the path may become more difficult, and the progress slower. But, with the Agnostic, to assign clearly defined boundaries to our cognitive powers is unjustifiable, for we pass gradually from one object to another without break, and there is no sharp limit betweenscience and metaphysics. The same instruments, principles, and methods that are recognized in the various sciences will carry us higher and higher, even to the Absolute, the First Cause, the Source of all reality. Induction will lead us from the effect to the cause, from the imperfect to the perfect, from the contingent to the necessary, from the dependent to the self-existent, from the finite to theinfinite.

And this same process by which we know God's existence cannot fail to manifest something—however little—of His nature and perfections. That we know Him imperfectly, by way chiefly of negation andanalogy, does not deprive this knowledge of all value. We can know God only so far as He manifests Himself through His works which dimly mirror His perfections, and so far as our finite mind will allow. Such knowledge will necessarily remain infinitely far from being comprehension, but it is only by a misleading confusion of terms that Spencer identifies the unknowable with the incomprehensible, and denies the possibility of any knowledge of the Absolute because we can have no absolute-knowledge. Seeing "through a glass" and "in a dark manner" is far from the vision "face to face" of which our limited mind is incapable without a special light from God Himself. Yet it is knowledge of Him who is the source both of the world's intelligibility and truth, and of the mind's intelligence. (See alsoAGNOSTICISM, CERTITUDE, EPISTEMOLOGY, FAITH.)