Philosophy

by Bertrand Russell

Hume’s criticism of the notion of cause was what led Kant to his new departure. Kant’s philosophy is difficult and obscure, and philosophers still dispute as to what he meant. Those who disagree with him are held by his supporters to have misunderstood him; I must therefore warn the reader that what follows is my view of what he meant, and that there is no agreed view.

Kant maintained that, in virtue of our mental constitution, we deal with the raw material of sense-impressions by means of certain “categories” and by arranging it in space and time. Both the categories and the space-time arrangement are supplied by us, and do not belong to the world except as known by us. But since our mental constitution is a constant datum, all phenomena as known will be spatio-temporal and will conform to the categories. Among the latter “cause” is the most important. Thus although there may be no cause in the world as it is in itself (a point on which Kant was inconsistent in the interest of morals), yet phenomena, i.e. things as they seem to us, will always have other phenomena as their causes. And although there is no time in the real world, things as they appear to us will be some earlier and some later. Space, again is supplied by us, and therefore geometry can be known a priori, without our having to study the outer world. Kant thought that Euclidean geometry was quite certainly true, although it could not be proved by logic alone, since Euclid’s axioms could be denied without self-contradiction.

It was on this question of geometry that the weakness of Kant’s system first became obvious. It was found that we have no grounds for regarding Euclidean geometry as quite true. Since Einstein, we have positive grounds for regarding it as not quite true. It appears that geometry is just as empirical as geography. We depend upon observation if we want to know whether the sum of the angles of a triangle is two right angles just as much as if we want to know how much land there is in the western hemisphere.

With regard to the “categories” there are equally great difficulties. Let us take “cause” as our illustration. We see lightning, and then we hear thunder; as phenomena, our seeing and hearing are connected as cause and effect. But we must not—if we are to take the subjectivity of “cause” seriously—suppose that our seeing or our hearing has an outside cause. In that case, we have no reason to suppose that there is anything outside ourselves. Nay, more: what really happens when we see is not, according to Kant, what we perceive by introspection; what really happens is something without a date, without a position in space, without causes and without effects. Thus we do not know ourselves any better than we know the outside world. Space and time and the categories interpose a mirage of illusion which cannot be penetrated at any point. As an answer to Hume’s scepticism, this seems a somewhat unsuccessful effort. And Kant himself, later, in the Critique of Practical Reason, demolished much of his own edifice, because he thought that ethics at least must have validity in the “real” world. This part of his philosophy, however, is usually ignored by his followers or apologetically minimised.

Kant gave a new turn to an old philosophical controversy, as to how far our knowledge is a priori and how far it is based on experience. Kant admitted that without experience we could know nothing, and that what we know is only valid within the realm of experience. But he held that the general framework of our knowledge is a priori in the sense that it is not proved by means of particular facts of experience, but represents the conditions to which phenomena have to conform in order to be capable of being experienced. Before his day, the tendency had been for continental philosophers to regard almost everything as a priori while British philosophers regarded almost everything as empirical. But both sides thought that what is a priori can be proved by logic, at least in theory, whereas Kant held that mathematics is a priori and yet “synthetic”, i.e. not capable of being proved by logic. In this he was misled by geometry. Euclidean geometry, considered as true, is “synthetic” but not a priori; considered merely as deducing consequences from premisses, it is a priori but not “synthetic”. The geometry of the actual world, as required by engineers, is empirical; the geometry of pure mathematics, which does not inquire into the truth of the axioms but merely shows their implications, is an exercise in pure logic.

It should be said, however, that, if the correct analysis of knowledge bears any resemblance at all to that which has been suggested in this book, the whole controversy between empiricists and apriorists becomes more or less unreal. All beliefs are caused by external stimuli; when they are as particular as the stimuli they are of the sort which an empiricist might regard as proved by experience, but when they are more general difficulties arise. A foreigner arrives in America and sees the immigration officials, who lead him to the generalisation that all Americans are rude; but a few minutes later the porter upsets this induction in the hope of a tip. Thus sometimes a given belief will be caused by one event and destroyed by another. If all the events in a man’s life, so far as they affect the belief in question, are such as to cause it, he counts the belief true. The more general a belief is, the more events are relevant to it, and therefore the more difficult it is for it to be such as a man will long consider true. Roughly speaking, the beliefs which count as a priori will be those which well might have been upset by subsequent events, but in fact were confirmed. Here as elsewhere we are driven to the view that theory of knowledge is not so fundamental as it has been considered since Kant.

There is one more traditional controversy which I wish to consider, namely, that between monists and pluralists. Is the universe one, or is it many? If many, how intimately are they interconnected? The monistic view is very old: it is already complete in Parmenides (fifth century B.C.). It is fully developed in Spinoza, Hegel, and Bradley. The pluralistic view, on the other hand, is found in Heraclitus, the atomists, Leibniz, and the British empiricists. For the sake of definiteness, let us take the monistic view as found in Bradley, who is in the main a follower of Hegel. He maintains that every judgment consists in assigning a predicate to Reality as a whole: the whole is the subject of every predicate. Suppose you start by saying “Tommy has a cold in the head”. This may not seem to be a statement about the universe as a whole, but according to Bradley it is. If I may be allowed to set forth his argument in popular language which his followers might resent, I should put it something like this: First of all, who is Tommy? He is a person with a certain nature, distinguished from other persons by that nature; he may resemble others in many respects, but not in all, so that you cannot really explain who Tommy is unless you set forth all his characteristics. But when you try to do this, you are taken beyond Tommy: he is characterised by relations to his environment. He is affectionate or rebellious or thirsty, noisy or quiet, and so on; all of these qualities involve his relations to others. If you try to define Tommy without mentioning anything outside him, you will find this quite impossible; therefore he is not a self-subsistent being, but an unsubstantial fragment of the world. The same thing applies even more obviously to his nose and his cold. How do you know he has a cold? Because material substances of a certain kind pass from his nose to his handkerchief, which would not be possible if he alone existed. But now, when you take in the environment with a view to defining Tommy and his nose and his cold, you find that you cannot define his immediate environment without taking account of its environment, and so on, until at last you have been forced to include the whole world. Therefore Tommy’s cold is in reality a property of the world, since nothing short of the world is sufficiently substantial to have properties.

We may put the argument in a more abstract form. Everything which is part of the world is constituted, in part, by its relations to other things; but relations cannot be real. Bradley’s argument against relations is as follows. First he argues that, if there are relations, there must be qualities between which they hold. This part of the argument need not detain us. He then proceeds:

“But how the relation can stand to the qualities is, on the other side, unintelligible. If it is nothing to the qualities, then they are not related at all; and, if so, as we saw, they have ceased to be qualities, and their relation is a nonentity. But if it is to be something to them, then clearly we shall require a new-connecting relation. For the relation hardly can be the mere adjective of one or both of its terms; or, at least, as such it seems indefensible. And, being something itself, if it does not itself bear a relation to the terms, in what intelligible way will it succeed in being anything to them? But here again we are hurried off into the eddy of a hopeless process, since we are forced to go on finding new relations without end. The links are united by a link, and this bond of union is a link which also has two ends; and these require each a fresh link to connect them with the old. The problem is to find how the relation can stand to its qualities, and this problem is insoluble.”

I cannot deal adequately with this argument without abstruse technicalities which would be out of place. I will, however, point out what seems to me the essential error. Bradley conceives a relation as something just as substantial as its terms, and not radically different in kind. The analogy of the chain with links should make us suspicious, since it clearly proves, if it is valid, that chains are impossible, and yet, as a fact, they exist. There is not a word in his argument which would not apply to physical chains. The successive links are united not by another link, but by a spatial relation. I think Bradley has been misled, unconsciously, by a circumstance to which I alluded in an earlier chapter, namely, the fact that the word for a relation is as substantial as the words for its terms. Suppose A and B are two events, and A precedes B. In the proposition “A precedes B”, the word “precedes” is just as substantial as the words “A” and “B”. The relation of the two events A and B is represented, in language, by the time or space order of the three words “A”, “precedes”, and “B”. But this order is an actual relation, not a word for relation. The first step in Bradley’s regress does actually have to be taken in giving verbal expression to a relation, and the word for a relation does have to be related to the words for its terms. But this is a linguistic, not a metaphysical, fact, and the regress does not have to go any further.