BOOKS

The Philosophy of Bertrand Russell

BY A. J.

AYER

BERTRAND RUSSELL is not only the most brilliant philosopher of this century : he is also one of the most self-critical. These qualities come out clearly in his philosophical auto- biography.* He begins it with a brief account of what he calls his present view of the world, which is less radically empiricist than some that he has held in the past. Its main features are that the physical world is not perceived by us but only inferred as the cause of our sensations, that what is inferable is not the content, the 'intrinsic charac- ter,' of physical events but only their structure, that 'the entities which occur in mathematical physics are not part of the stuff of the world,' since they can be treated as logical constructions out of events, which may themselves be further analys- able, that the spatio-temporal ordering of physical events is bound up with causation, inasmuch as it depends upon the fact that certain physical processes are irreversible, that the things which we immediately perceive, the data of which we are aware without inference, are private to ourselves and are located in private space, that these private spaces are mirrors of public space, and that since our sensations may be identified with occurrences in our brains, these private spaces and all that they contain are physically located in the per- cipients' heads. Thus, whereas most people would suppose that we never observe what is going on inside our heads, Russell maintains in a sense that we not only do observe this, but never observe anything else.

Russell remarks that his theory of public and Private spaces has a close affinity with the mona- dology of Leibniz, but it seems to me that in general his position is more akin to that of Locke. The structural properties of physical events, which Russell thinks we are entitled to infer, correspond to the 'primary qualities' which Locke attributed

to physical objects. In both cases there is the difficulty of validating the transition from the private world of 'ideas' or percepts to the public World of physical things. For instance, it is not at all clear to me how, if we can perceive only what , k physically located in our own heads, we can he in a position even to conjecture where the ' external causes of our sensations really are in I Physical space. Russell indeed does not claim that 1 his theory can be proved : but he does think that

it accounts for the appearances better than any other.

The main purpose of his book, however, is not

to defend this theory but to give a historical account of the ways in which his views have changed and developed throughout his long career as a philosopher. He tells us that he first began to think about philosophical questions at the age of fifteen, partly because of his interest in mathe- olatics, but mainly because he was then starting to have doubts about the truth of the religion in Which he had been brought up. He reproduces Passages from the diary whin he kept in the spring of 1888, just before and after his sixteenth birth- day; their tone is astonishingly mature. At Cam- * My PHILOSOPHICAL DEVELOPMENT. By Bertrand Russell. (Allen and Unwin, 18s.) bridge he began by reading mathematics, but turned in his fourth year to philosophy. Mainly under the influence of McTaggart, he embraced a form of idealist metaphysics, which owed some- thing to Kant but more to Hegel. It was in this spirit that he wrote, as his fellowship thesis, An Essay on the Foundations of Geometry, which was published in 1897 and was the first of his many philosophical books.

This Hegelian period lasted until 1898. But at the end of that year Russell followed G. E. Moore in a revolt against any form of absolute idealism. In particular, he rejected the idealist 'dogma of internal relations,' and with it the coherence theory of truth and the view that everything is One. Two years later a meeting with the Italian logician, Peano, at a congress in Paris aroused Russell's interest in symbolic logic. The first fruits of this, and of the realist and pluralist outlook which he shared with Moore, were displayed in The • Principles of Mathematics, perhaps the most fertile book that he has ever written in philosophy, which appeared in 1903. Throughout this decade he con- centrated mainly on mathematical logic and his work in this field culminated in the monumental Prirrcipia Mathematica, which he wrote in such close collaboration with Whitehead that he now says that 'there is hardly a line in all three volumes that is not a joint product.' On the other hand, he also says that broadly speaking Whitehead left the philosophical problems to him, and it is to Russell that we owe the theory of descriptions and also the discovery of the logical contradiction which he met by devising the theory of types. This difficulty was encountered almost at the beginning of their work and led Whitehead to quote 'never glad, confident morning again.' How far Russell and Whitehead succeeded in overcoming this and other difficulties, and so in fulfilling their pro- gramme of reducing mathematics to logic, is still a matter for dispute. Russell himself complains in this book that the purely mathematical aspect of their work has been insufficiently studied. What is not in dispute is that Principia Mathematica is a landmark in the history of logic.

With Principia Mathematica bet) i nd him Russell turned his attention to the theory of knowledge.

This yielded The Problems of Philosophy which was published in the Home University Library,

and is still to my mind the best of all introductory

books on the subject, and Our Knowledge of the External World, in which Russell, employing a technique which had been suggested to him by

Whitehead, tried to exhibit physical objects, not as inferred entities, but as logical constructions out of the material given to sense. He carried this logical economy to its furthest point a few years

later in the Analysis of Mind. Accepting William James's idea that the stuff of the world is neutral

in the sense of being neither mental nor physical, he tried to show that both mind and matter could be constructed out of sense-data and images. This is very much the philosophy of Hume, in modern guise.

The theory of logical atomism, with which Russell is also credited, owes a good deal to Wittgenstein, who was his pupil at Cambridge just before the First World War. This is the Wittgenstein of the Tractatus, not of the Philoso- phical Investigations, of which Russell dis- approves. Wittgenstein confirmed Russell in the view that analysis ideally terminates in statements which picture absolutely simple facts : a view which survives, with fairly serious reservations, in Russell's Inquiry into Meaning and Truth, which deals in a very stimulating way with problems of linguistics, and also in Human Knowledge: Its Scope and Limits, which is otherwise chiefly notable for its treatment of the problems of non- demonstrative inference. But the most important effect that Wittgenstein had on Russell was to con- vince him that the propositions of pure mathe- matics are tautologies. It is partly for this reason that Russell speaks in this book of the develop- ment of his philosophy in the last fifty years as a 'retreat from Pythagoras.'

Russell tells this story with his usual economy, wit and elegance. Little of it will be new to students of philosophy : it is indeed largely sustained by quotations from his published works. But I for one was surprised to discover how serious his early 'excursion into idealism' was. His paper on 'The Relations of Number and Quantity,' described by him now as 'unmitigated rubbish,' but by Couturat at the time as`ce petit chef d'oeuvre de dialectique subtile,' and his notes on the philosophy of physics, which, after more than sixty years, are here pub- lished for the first time, show what a formidable Hegelian he might have made if he had not been preserved by his 'robust feeling for reality.'

In his introductory chapter Russell reaffirms his belief that progress in philosophy is possible only through analysis : but, as we now know, philo- sophical analysis can take many forms. For Russell it serves the theory of knowledge : the more entities one can dispense with, the smaller are one's chances of being wrong. In fact his method has always been constructive rather than analytical. He starts with propositions of the-truth of which we can be reasonably certain and tries to find ways of basing other propositions upon them. Thus he has no liking for the modern fashion of treating linguistic analysis as an end in itself : and he concludes his book by reprinting three recent articles in which he defends his ideas against contemporary Oxford philosophers, to- gether with a critical review of Professor Ryle's Concept of Mind.

On this issue my own sympathies lie with Russell. I think that he makes out a good case against both Urmson and Warnock, and that he succeeds in showing that Ryle's dismissal of 'the ghost in the machine' was in some ways rather cavalier. On the other hand, there is one important point in his defence of his theory of descriptions against Strawson, where I think that he is in the wrong. He still maintains that 'if language is to have any relation to fact,' there must be some words 'which are only significant because there is something that they mean.' But surely all that is needed is that there be some words which are capable of referring to what could be observed.

Whether they succeed in their reference is, in any given case, a question of empirical fact, which lies outside semantics. This does not, however, in- validate the theory of descriptions, though it may affect one of the motives that Russell had for putting it forward.

The volume ends with the preface and introduc- tion to a book about Russell's philosophy on which his biographer, Alan Wood, was working when he died. There is nothing objectionable in these twenty pages : but as an expositor of Rus- sell's ideas, Wood does not stand comparison with Russell himself.