The nature of knowing

Kinds of communication

The communication between lifeless bodies is limited strictly to an immediate physical impact, a momentary instant of contact an entirely surface communication. A purely physical being receives another being only in the most superficial manner as a cup takes in water or a pail, sand. Any more intimate communication means that physical things lose their identity, becoming something else; the union of hydrogen and oxygen, for example, results in a third thing, water. The being of a plant is richer than the being of a lifeless body, for the plant can take in other substances and make them its own without losing its identity. It can grow and reproduce itself. Its world is still a lonely and a private one, however, for like the lifeless body its range is limited to the area of direct physical contact. To the immediate moment, too, for there is no past or future for plants no past, for the past is no longer; no future, for the future too is not physically present. The horizon begins to expand when we reach the level of animal consciousness, of sensation. The animal is affected not only by those bodies with which it has immediate physical contact, but it is also in intimate relationship with other things at a distance. It can see food across the meadow and walk toward it. It can see an enemy in the distance and run away from it. The way an animal receives things is vastly superior to the mere physical taking in of plants and inert bodies, but the animal’s world is still a private and a closed world. Its horizon is bounded by the physical range of the senses-the limits of vision, sound, smell, the particularities of sense memory; it is submerged, too, in the sea of feeling and instinct. Only in the case of man do we find the limitations of physical existence transcended. Because man in knowing can take in the forms of other beings, not only in their mere surface aspects, but in their inner reality, his own being is enlarged, enriched both by the whole universe of bodies to which he gives a new existence in the act of knowing, and by the realm of the spiritual itself, which he reaches through the twin powers of intellect and will. Nor is man enclosed in the particular moment, for the past lives in his memory and he gives the future a kind of being by anticipation. (This is dimly foreshadowed in the higher forms of animal knowing.) The nature of man is such, then, that he is able to take in the whole universe and make it his own, without at the same time losing his own identity. “Beings that know” says St. Thomas, “are superior to beings that do not know because beings that do not know have only their own forms, while the being that knows is such that it is able to receive the form of the other.”

Change involved in knowing = immaterial

Here we have a very great mystery the fact that the soul can become, as Aristotle says, all things, while at the same time remaining itself. For in the act of knowing we make the things we know part of ourselves-not in any physical way, in the manner, for example, in which we make food a part of ourselves, but in a way which leaves unchanged both our own physical being and that of the object known. The kind of union that takes place between the knower and the thing known is different from any physical union, represents a kind of change for which there is no counterpart in the world of bodies. Change in material things below the level of animals, as we have seen, always means some new physical determination which did not exist before a new third thing, the product of the union of matter with a new form. The change that takes place in knowing, on the other hand, does not result in any new physical determination, either on the part of the thing known or of the knower. I know the fire of the sun, for example, without myself being on fire. Nor is the fire changed by my knowing it. Since the change brought about by the knowledge is not, then, something physical or material, we have to term it nonmaterial or immaterial.

Knower becomes the thing known

The soul of man rises above the limitations of matter and hence can become the other, the thing known, without being physically changed can know stones without being petrified, cats without becoming feline, fire without becoming hot. By the same token we can know contraries at the same time sweet and sour, hard and soft, black and white; and we can know ourselves-can stand off to one side, so to speak, and see ourselves both as knower and thing known.

The first assimilation of form without matter is found in sense knowing, where the sensible forms color, sound, consistency, temperature, and so on are received immaterially; we receive the color of gold, for example, without receiving gold itself. But although the sensible forms are thus separated from matter, they are received under the conditions of matter, for sensation is always the act of a bodily organ upon whose physical alteration it is dependent. This dependence on the material sense organ is reflected in the character of sense knowledge which is always particular and individual.

Intellectual knowledge, in contrast to sense knowledge, is of the universal, because the intellect raises the things it knows to its own level, giving them a share in its own unalloyed immateriality and thereby giving them a new kind of existence. It gives them a new existence without robbing them of their old. For what happens in the act of knowing is that the same thing, identically the same thing, exists in the intellect as exists outside. To know a thing is to live it, to give it a new birth; it is literally to be that thing, in the way of being proper to the intellect.

Intentional existence

How is it possible for us to be another thing, a tree, for example, and still retain our identity as human beings? St. Thomas explains that this is possible because the same form is capable of existing in more than one way. Besides the existence of nature by which form is united with matter in the act of physical existence, there is another kind of existence which St. Thomas calls intentional existence a nonphysical existence, a kind of superexistence which the intellect gives to things when it knows them. Thus it is not a mere copy or image of the thing that we know. If that were the case we would never be sure that the image or representation was exactly like the object it was supposed to represent. We would know images, not things. What I know is the form itself of the thing, present in me not in a physical way but in an immaterial mode of existence. In union with the principle of matter, the form constitutes this concrete, individual oak tree. Joined to the intellect, the same form becomes the abstract, immaterial “treeness.”

In other words, what the thing is is the same in the intellect and in the thing, though the kind of existence is different. St. Thomas, using the nature of man as an example, points out that, strictly speaking, there is implied in the nature of man just those notes which express the ultimate structure of this nature animality and rationality. Neither individuality nor universality is implied in the nature of man.

The pure essence, so to speak, of man is indifferent as to whether it is found in the concrete individual human being, or in the universal idea of man in the intellect. “The nature of man absolutely considered abstracts from any kind of existence, in such a way however that it does not exclude any of them,” St. Thomas says? Thus, by distinguishing between what a thing is, or its essence, and its “is-ness,” or that whereby it exercises the act of existence, we can say that the same reality is both in the external object in its physical, material mode of existence and in the intellect in its universal, immaterial mode of existence.