Recent Developments in European Thought

by Unknown

This last remark leads me to a further consideration. Science and Philosophy are alike created by the simple determination to be thorough in our thinking about the problems which all things and events present to us, to use no terms whose meaning is ambiguous, to assert no propositions as true until we are satisfied that they are either directly apprehended as true, or strictly deducible from other propositions which are thus apprehended. But now that the area of facts open to our exploration has become far too vast for a modern Francis Bacon to 'take all knowledge for his province', and convenience has led to the distinction between the philosopher and the man of science, a practical distinction between the two makes its appearance. It is convenient that our knowledge of detail should be steadily extended by considering the consequences which follow from a given set of postulates without waiting for the solution of the more strictly philosophical questions whether our postulates have been reduced to the simplest and most unambiguous expression, whether the list might not be curtailed by showing that some of its members which have been accepted on their own merits can be deduced from the rest, or again enlarged by the express addition of principles which we have all along been using without any actual formulation of them. The point may be illustrated by considering the set of 'postulates' explicitly made in the geometry of Euclid. We cannot be said to have made geometry thoroughly scientific until we know whether the traditional list of postulates is complete, whether some of the traditional postulates might not be capable of demonstration, and whether geometry as a science would be destroyed by the denial of one or more of the postulates. But it would be very undesirable to suspend examination of the consequences which follow from the Euclidean postulates until we have answered all these questions. Even in pure mathematics one has, in the first instance, to proceed tentatively, to venture on the work of drawing inferences from what seem to be plausible postulates before one can pass a verdict on the merits of the postulates themselves. The consequence of this tentative character of our inquiries is that, so far as there is a difference between Philosophy and Science at all, it is a difference in thoroughness. The more philosophic a man's mind is, the less ready will he be to let an assertion pass without examination as obviously true. Thus Euclid makes a famous assumption—the 'parallel-postulate'—which amounts to the assertion that if three of the angles of a rectilinear quadrilateral are right angles, the fourth will be a right angle. The mathematicians of the eighteenth and early nineteenth centuries, again, generally assumed that if a function is continuous it can always be differentiated. A comparatively unphilosophical mind may let such plausible assertions pass unexamined, but a more philosophical mind will say to itself, when it comes across them, 'You great duffer, aren't you going to ask Why?' Suppose that, by way of experiment, I assume that the fourth angle of my quadrilateral will be acute, or again obtuse, will the body of conclusions I can now deduce from my set of postulates be free from contradictions or not? If I really give my mind to the task, cannot I define a continuous function which is not differentiable? The raising of the first question led in fact to the discovery of what is called 'non-Euclidean' geometry, the raising of the second has banished from the text-books of the Calculus the masses of bad reasoning which long made that branch of mathematics a scandal to logic and led distinguished philosophers—Kant among them—to suspect that there are hopeless contradictions in the very foundations of mathematical science.

Now, the effect of such careful scrutiny of first principles is not, of course, to upset any conclusions which have been correctly drawn from a set of premisses. All that happens is that the conclusion is no longer asserted by itself as a truth; what is asserted is that the conclusion is true if the premisses are true. Thus we no longer assert the 'theorem of Pythagoras' as a categorical proposition; what we assert is that the theorem follows as a consequence from the assertion of some half-dozen ultimate postulates which will be found on analysis to be the premisses of Euclid's proof of his forty-seventh proposition.

To come back to the point I wish to illustrate. The peculiarity of the philosopher is simply that he still goes on to 'wonder' and ask Why when other persons are ready to leave off. He is less contented than other men to take things for granted. Of course, he knows that, in the end, you cannot get away from the necessity of taking something for granted, but he is anxious to take for granted as few things as possible, and when he has to take something for granted, he is exceptionally anxious to know exactly what that something is. De Morgan tells a story of a very pertinacious controversialist who, being asked whether he would not at least admit that 'the whole is greater than the part', retorted, 'Not I, until I see what use you mean to make of the admission.' I am not sure whether De Morgan quotes this as an ensample for our following or as a warning for our avoidance, but to my own mind it is an excellent specimen of the philosophic temper. Until you know what use is going to be made of your admission, you do not really know what it is you have admitted. It is this superior thoroughness of Philosophy which Plato has in mind when he says of his supreme science 'Dialectic' that its business is to examine and even to 'destroy' ([Greek: anairein]) the assumptions of all the other sciences. It does not let propositions which they have been content to take for granted pass without challenge, and it may actually 'destroy' them by showing that there is no justification for asserting them. Thus Euclid's assumption about parallels ceased to be included among the indispensable premisses of geometry, and was 'destroyed' in Plato's sense when Lobatchevsky, Bolyai, and Riemann showed that complete bodies of self-consistent geometrical theory can be deduced from sets of postulates in which Euclid's assumption is explicitly denied. There are two further points I should like to put before you in this connexion. One of them has been forcibly argued by Mr. Bertrand Russell in his admirable little work The Problems of Philosophy; the other has not. Indeed, it is just in his unwillingness to allow the second of these points to be raised at all that Mr. Russell seems to me to fall conspicuously and unaccountably short of being what, by his own showing, a great philosopher ought to be.

To take first the point with which Mr. Russell has dealt. There is one very important branch of inquiry, if we ought not rather to say that there are two, which appear to belong wholly to general Philosophy and not to any of the 'sciences'. We cannot so much as ask the simplest question without making the implication that there is an ultimate distinction between true assertions and false ones, and certain definite principles by which we can infer true conclusions from true premisses. It is thus a very important part of the true 'story of everything' to state the principles upon which valid reasoning depends, and to enunciate the ultimate postulates which have to be taken for granted whenever we try to reason validly about anything. This is the inquiry known by the name of logic. We cannot expect men whose time is fully taken up with the task of reaching true conclusions about some special class of facts, those which concern the history of living organisms, or the production and distribution of 'wealth', or the stability of various forms of government, to burden themselves with this inquiry in addition to their other tasks. They may fairly be allowed to leave the construction of logic to others. But the man who makes it the business of his life to get back to ultimate first principles must plainly be a logician, though he need not be a specialist in biology or economics or 'sociology'. One great advantage which our children should have over their parents as students of Philosophy is that the last half-century has been one of unprecedented advance in the study of logic. In the 'logic of relations', founded by De Morgan, carried out further in the third volume of Ernst Schröder's Algebra der Logik, and made still more precise in the earliest sections of the Principia Mathematica of Whitehead and Russell, we now possess the most potent weapon of intellectual analysis ever yet devised by man.

We must further remark that the serious pursuit of any kind of science implies not only that there are truths, but that some of them, at least, can be known by man. Hence there arises a problem which is not quite the same as that of logic. What is the relation we mean to speak of when we talk of 'knowing' something, and what conditions must be fulfilled in order that a proposition may not only be true but be known by us to be true? The very generality of this problem marks it out as one which belongs to what I have been all along calling Philosophy. (We must be careful to note that the problem does not belong to the 'special science' of psychology. Psychology aims at telling us how particular thoughts and trains of thought arise in an individual mind, but it has nothing to say on the question which of our thoughts give us 'knowledge' and which do not. The 'possibility of knowledge' has to be presupposed by the psychologist as a pre-condition of his particular investigations exactly as it is presupposed by the physicist, the botanist, or the economist.) The study of the problem 'what are the conditions which must be satisfied whenever anything at all is known' is precisely what Kant meant by Criticism, though the raising of the problem in this definite form is not due to Kant but goes back to Plato, who made it the subject of one of his greatest dialogues, the Theaetetus. The simplest way to make the nature and importance of the problem clear is perhaps the way Mr. Russell adopts in the Problems of Philosophy—to give a very rough statement of Kant's famous solution.

Kant held that careful analysis shows us that any piece of knowledge has two constituents of very diverse origin. It has a matter or material constituent consisting, as Kant held, of certain crude data supplied by sensation, colours, tones of varying pitch and loudness, odours, savours, and the like. It has also a form or formal constituent. Our data, when we know anything at all, are arranged on some definite principle of order. When we recognize an object by the eye or a tune by the ear, we do not apprehend simply so much colour or sound, but colours spread out and forming a pattern or notes following one another in a fixed order. (If you reverse the movement of a gramophone, you get the same notes as before, but you do not get the same tune.) Further, Kant thought it could be shown that the data of our knowledge are a disorderly medley and come to us from without, being supplied by things which exist and are what they are equally whether any one perceives them or not, but the element of form, pattern, or order is put into them by our own minds in the act of knowing them. Our minds are so constructed that we can only perceive things or think of them as connected by certain definite principles of orderly arrangement. This, he thought, explains the indubitable fact that we can sometimes know universal propositions to be true without needing to examine all the individual instances. I can know for certain that in every triangle the greater angle is subtended by the greater side, or that every event has a definite cause among earlier events, though I cannot examine all triangles or all events one by one. This is because the postulates of geometry and the law of causality are types of order which my mind puts into the data of its knowledge in the very act of attending to them, and it is therefore certain that I shall never perceive or think anything which does not conform to these types.

I give Kant's answer to the problem of Criticism not because I believe it to be the correct one, but to show what important consequences follow from our acceptance of a solution of this problem. If it is true that one of the constituent elements of every piece of knowledge is a lump of crude sensation, it follows that we can have no knowledge about our own minds or souls, and still less about God, since, if there are such beings as my soul and God, at any rate neither furnishes me with sense-data. Hence a great part of Kant's famous Critique of Pure Reason is taken up by an elaborate attempt to show that psychology and theology contain no real knowledge. We cannot even know whether there is any probability for or against the existence of the soul or of God, though Kant was very anxious to show that it is our duty on moral grounds to believe very firmly in both. Now if Kant is right about this, his result is tremendously important. If psychology and theology are wholly devoid of scientific value, it is most desirable that we should know this, not only that we may not waste time in studying them, but because it may reasonably make a very great difference to the practical ordering of our lives. If Kant can be proved wrong, it is equally important to be convinced that he is wrong. We may have been led by belief in his teaching to neglect the acquisition of a great deal of knowledge of high intrinsic interest, and may even have been betrayed into basing the conduct of life on wrong principles. If, for example, we can really know something about the soul, it may be possible to know whether it is immortal or not, and it is not unreasonable to hold that certain knowledge, or even probable belief, on such a point ought to make a great difference to our choice between rival aims in life. There is clearly much less to be said for the recommendation to 'eat and drink for to-morrow we die' if we have reason to believe our souls immortal than if we have not, and some of us do not share Mr. Russell's view that Philosophy is called upon to abdicate what the Greeks thought her sovereign function, the regulation of life. It is true that Kant convinced himself that it is a moral duty to act as if we knew the truth of doctrines for or against which we cannot detect the slightest balance of probability. But the logically sound inference from Kant's premisses would be that, to use Pascal's famous metaphor, a prudent man will do well to bet neither for nor against immortality. Unfortunately, as Pascal said, you can't help betting; il faut parier. If it makes any difference to the relative values of different goods whether the soul dies with the body or not, one must take sides in the matter. In making one's choices one must prefer either the things it is reasonable to regard as good for a creature whose days are threescore years and ten or those which it is reasonable to regard as best for a being who is to live for ever. The only way to escape having to bet is not to be born.

I come to the second problem, the one which, as I think, Mr. Russell arbitrarily ignores. A human being is not a mere knowledge-machine. The relation of knower to known is not the only relation in which he stands to himself and to other things. The 'world' is not merely something at which he can look on, it is also an instrument for achieving what he regards as good and for creating what he judges to be beautiful. To do good and to make beautiful things are just as much man's business as to discover truth. A knowledge of the world would be very incomplete if it did not include knowledge of what ought to be, whether because it is morally best or because it is beautiful, as well as knowledge of what is actually there. And it is not immediately evident how the two, knowledge of what ought to be and knowledge of what merely is, are connected.

There is, to be sure, one way in which it is pretty plain that they are not related. You cannot learn what ought to be—what is beautiful or morally good—merely by first finding out what has been or what is likely to be. This simple consideration of itself deprives many of the big volumes which have been written about the 'evolution' of art and morals of most of their value. They may have interest if they are treated only as contributions to the history of opinion about art and morals. But unhappily their authors often assume that we can find out what really is right or beautiful by merely discovering what men have thought right and beautiful in the remote past or guessing what they will think right or beautiful in the distant future. The fallacy underlying this procedure has been happily exposed by Mr. Russell himself in an occasional essay where he remarks that it is antecedently just as likely that evolution is going from bad to worse as that it is going from good to better. Unless it is going from bad to worse it is obviously absurd to suppose that you can find out what is good by discovering what our distant ancestors thought good. And if (as may be the case) it is going from bad to worse, no amount of knowledge about what our posterity will think good can throw any light on the question what is good. There is, in fact, no ground whatever for believing that 'evolution' need be the same thing as progress, and this is enough to knock the bottom out of 'evolutionary ethics'.

On the other hand, it is quite certain that when we call an act right or a picture beautiful we do not mean to be expressing a mere personal liking of our own, any more than when we make a statement about the composition of sulphuric acid or the product of 9 and 7. As Dr. Rashdall has put it, when we say that a given act is right, we do not pretend to be infallible. We know that we may fall into mistakes about right and wrong just as we may make mistakes in working a multiplication sum. But we do mean to say that if our own verdict 'that act is right' is a true one, then the verdict of any one who retorts 'that act is wrong' is false, just as when we state the result of our multiplication we mean to assert that if we have done the sum correctly any one else who brings out a different answer has worked it wrongly. Indeed, we might convince ourselves that these verdicts are not meant to be expressions of private and personal liking in a still simpler way. All of us must be aware that the line of action we pronounce 'right' is not always what we like nor the conduct we call 'wrong' what we dislike. We often like doing what we fully believe to be wrong and dislike doing what we believe right, without being in the least confused in our moral verdicts by this collision of liking and conviction. So again it is a common thing to like one poem or picture better than another, and yet to be fully persuaded that the work we like the less is the better work of art. Indeed, the whole process of moral and aesthetic education may be said to exist just in learning to like most what is really best.