Kant's Theory of Knowledge

by H. A. Prichard

It may, however, be replied that the supposed consequence, though absurd, does not really follow from the plain man's realism. Doubtless, it would be impossible for a universe consisting solely of the physical world to originate thought or beings capable of thinking. But the real presupposition of the coming into existence of human knowledge at a certain stage in the process of the universe is to be found in the pre-existence, not of a mind or minds which always actually knew, but simply of a mind or minds in which, under certain conditions, knowledge is necessarily actualized. A mind cannot be the product of anything or, at any rate, of anything but a mind. It cannot be a new reality introduced at some time or other into a universe of realities of a wholly different order. Therefore, the presupposition of the present existence of knowledge is the pre-existence of a mind or minds; it is not implied that its or their knowledge must always have been actual. In other words, knowing implies the ultimate or unoriginated existence of beings possessed of the capacity to know. Otherwise, knowledge would be a merely derivative product, capable of being stated in terms of something else, and in the end in terms of matter and motion. This implication is, however, in no wise traversed by the plain man's realism. For that implies, not that the existence of the physical world is prior to the existence of a mind, but only that it is prior to a mind's actual knowledge of the world.

The second line of thought appeals to the logic of relation. It may be stated thus. If a term is relative, i. e. is essentially 'of' or relative to another, that other is essentially relative to it. Just as a doctor, for instance, is essentially a doctor of a patient, so a patient is essentially the patient of a doctor. As a ruler implies subjects, so subjects imply a ruler. As a line essentially has points at its ends, so points are essentially ends of a line. Now knowledge is essentially 'of' or relative to reality. Reality, therefore, is essentially relative to or implies the knowledge of it. And this correlativity of knowledge and reality finds linguistic confirmation in the terms 'subject' and 'object'. For, linguistically, just as a subject is always the subject of an object, so an object is always the object of a subject.

Nevertheless, further analysis of the nature of relative terms, and in particular of knowledge, does not bear out this conclusion. To take the case of a doctor. It is true that if some one is healing, some one else is receiving treatment, i. e. is being healed; and 'patient' being the name for the recipient of treatment, we can express this fact by saying that a doctor is essentially the doctor of a patient. Further, it is true that a recipient of treatment implies a giver of it, as much as a giver of it implies a recipient. Hence we can truly say that since a doctor is the doctor of a patient, a patient is the patient of a doctor, meaning thereby that since that to which a doctor is relative is a patient, a patient must be similarly relative to a doctor. There is, however, another statement which can be made concerning a doctor. We can say that a doctor is a doctor of a human being who is ill, i. e. a sick man. But in this case we cannot go on to say that since a doctor is a doctor of a sick man, a sick man implies or is relative to a doctor. For we mean that the kind of reality capable of being related to a doctor as his patient is a sick man; and from this it does not follow that a reality of this kind does stand in this relation. Doctoring implies a sick man; a sick man does not imply that some one is treating him. We can only say that since a doctor is the doctor of a sick man, a sick man implies the possibility of doctoring. In the former case the terms, viz. 'doctor' and 'patient', are inseparable because they signify the relation in question in different aspects. The relation is one fact which has two inseparable 'sides', and, consequently, the terms must be inseparable which signify the relation respectively from the point of view of the one side and from the point of view of the other. Neither term signifies the nature of the elements which can stand in the relation. In the latter case, however, the terms, viz. 'doctor' and 'sick man', signify respectively the relation in question (in one aspect), and the nature of one of the elements capable of entering into it; consequently they are separable.

Now when it is said that knowledge is essentially knowledge of reality, the statement is parallel to the assertion that a doctor is essentially the doctor of a sick man, and not to the assertion that a doctor is essentially the doctor of a patient. It should mean that that which is capable of being related to a knower as his object is something which is or exists; consequently it cannot be said that since knowledge is of reality, reality must essentially be known. The parallel to the assertion that a doctor is the doctor of a patient is the assertion that knowledge is the knowledge of an object; for just as 'patient' means that which receives treatment from a doctor, so 'object' means that which is known. And here we can go on to make the further parallel assertion that since knowledge is essentially the knowledge of an object, an object is essentially an object of knowledge. Just as 'patient' means a recipient of treatment, or, more accurately, a sick man under treatment, so 'object' means something known, or, more accurately, a reality known. And 'knowledge' and 'object of knowledge', like 'doctor' and 'patient', indicate the same relation, though from different points of view, and, consequently, when we can use the one term, we can use the other. But to say that an object (i. e. a reality known) implies the knowledge of it is not to say that reality implies the knowledge of it, any more than to say that a patient implies a doctor is to say that a sick man implies a doctor.

But a doctor, it might be objected, is not a fair parallel to knowledge or a knower. A doctor, though an instance of a relative term, is only an instance of one kind of relative term, that in which the elements related are capable of existing apart from the relation, the relation being one in which they can come to stand and cease to stand. But there is another kind of relative term, in which the elements related presuppose the relation, and any thought of these elements involves the thought of the relation. A universal, e. g. whiteness, is always the universal of certain individuals, viz. individual whites; an individual, e. g. this white, is always an individual of a universal, viz. whiteness. A genus is the genus of a species, and vice versa. A surface is the surface of a volume, and a volume implies a surface. A point is the end of a line, and a line is bounded by points. In such cases the very being of the elements related involves the relation, and, apart from the relation, disappears. The difference between the two kinds of relative terms can be seen from the fact that only in the case of the former kind can two elements be found of which we can say significantly that their relation is of the kind in question. We can say of two men that they are related as doctor and patient, or as father and son, for we can apprehend two beings as men without being aware of them as so related. But of no two elements is it possible to say that their relation is that of universal and individual, or of genus and species, or of surface and volume; for to apprehend elements which are so related we must apprehend them so related.[7] To apprehend a surface is to apprehend a surface of a volume. To apprehend a volume is to apprehend a volume bounded by a surface. To apprehend a universal is to apprehend it as the universal of an individual, and vice versa.[8] In the case of relations of this kind, the being of either element which stands in the relation is relative to that of the other; neither can be real without the other, as we see if we try to think of one without the other. And it is at least possible that knowledge and reality or, speaking more strictly, a knower and reality, are related in this way.

What is, however, at least a strong presumption against this view is to be found in the fact that while relations of the second kind are essentially non-temporal, the relation of knowing is essentially temporal. The relation of a universal and its individuals, or of a surface and the volume which it bounds, does not either come to be, or persist, or cease. On the other hand, it is impossible to think of a knowing which is susceptible of no temporal predicates and is not bound up with a process; and the thought of knowing as something which comes to be involves the thought that the elements which become thus related exist independently of the relation. Moreover, the real refutation of the view lies in the fact that, when we consider what we really think, we find that we think that the relation between a knower and reality is not of the second kind. If we consider what we mean by 'a reality', we find that we mean by it something which is not correlative to a mind knowing it. It does not mean something the thought of which disappears with the thought of a mind actually knowing it, but something which, though it can be known by a mind, need not be actually known by a mind. Again, just as we think of a reality as something which can stand as object in the relation of knowledge, without necessarily being in this relation, so, as we see when we reflect, we think of a knowing mind as something which can stand as subject in this relation without necessarily being in the relation. For though we think of the capacities which constitute the nature of a knowing mind as only recognized through their actualizations, i. e. through actual knowing, we think of the mind which is possessed of these capacities as something apart from their actualization.

It is now possible to direct attention to two characteristics of perception and knowledge with which Kant's treatment of space and time conflicts, and the recognition of which reveals his procedure in its true light.

It has been already urged that both knowledge and perception—which, though not identical with knowledge, is presupposed by it—are essentially of reality. Now, in the first place, it is thereby implied that the relation between the mind and reality in knowledge or in perception is essentially direct, i. e. that there is no tertium quid in the form of an 'idea' or a 'representation' between us as perceiving or knowing and what we perceive or know. In other words, it is implied that Locke's view is wrong in principle, and, in fact, the contrary of the truth. In the second place, it is implied that while the whole fact of perception includes the reality perceived and the whole fact of knowledge includes the reality known, since both perception and knowledge are 'of', and therefore inseparable from a reality, yet the reality perceived or known is essentially distinct from, and cannot be stated in terms of, the perception or the knowledge. Just as neither perception nor knowledge can be stated in terms of the reality perceived or known from which they are distinguished, so the reality perceived or known cannot be stated in terms of the perception or the knowledge. In other words, the terms 'perception' and 'knowledge' ought to stand for the activities of perceiving and knowing respectively, and not for the reality perceived or known. Similarly, the terms 'idea' and 'representation'—the latter of which has been used as a synonym for Kant's Vorstellung—ought to stand not for something thought of or represented, but for the act of thinking or representing.

Further, this second implication throws light on the proper meaning of the terms 'form of perception' and 'form of knowledge or of thought'. For, in accordance with this implication, a 'form of perception' and a 'form of knowledge' ought to refer to the nature of our acts of perceiving and knowing or thinking respectively, and not to the nature of the realities perceived or known. Consequently, Kant was right in making the primary antithesis involved in the term 'form of perception' that between a way in which we perceive and a way in which things are, or, in other words, between a characteristic of our perceiving nature and a characteristic of the reality perceived. Moreover, Kant was also right in making this distinction a real antithesis and not a mere distinction within one and the same thing regarded from two points of view. That which is a form of perception cannot also be a form of the reality and vice versa. Thus we may illustrate a perceived form of perception by pointing out that our apprehension of the physical world (1) is a temporal process, and (2) is conditioned by perspective. Both the succession and the conditions of perspective belong to the act of perception, and do not form part of the nature of the world perceived. And it is significant that in our ordinary consciousness it never occurs to us to attribute either the perspective or the time to the reality perceived. Even if it be difficult in certain cases, as in that of colour, to decide whether something belongs to our act of perception or not, we never suppose that it can be both a form of perception and a characteristic of the reality perceived. We think that if it be the one, it cannot be the other.

Moreover, if we pass from perception to knowledge or thought—which in this context may be treated as identical—and seek to illustrate a form of knowledge or of thought, we may cite the distinction of logical subject and logical predicate of a judgement. The distinction as it should be understood—for it does not necessitate a difference of grammatical form—may be illustrated by the difference between the judgements 'Chess is the most trying of games' and 'Chess is the most trying of games'. In the former case 'chess' is the logical subject, in the latter case it is the logical predicate. Now this distinction clearly does not reside in or belong to the reality about which we judge; it relates solely to the order of our approach in thought to various parts of its nature. For, to take the case of the former judgement, in calling 'chess' its subject, and 'most trying of games' its predicate, we are asserting that in this judgement we begin by apprehending the reality of which we are thinking as chess, and come to apprehend it as the most trying of games. In other words, the distinction relates solely to the order of our apprehension, and not to anything in the thing apprehended.