Une raison possible d'arrêter de faire de la philosophie.
C'est Isaiah Berlin qui préface ainsi la réédition d'anciens articles de philosophie dans Concepts and categories (Pimlico, 1978, p.XI-XII) :
" I have occasionnaly been asked what made me cease to teach philosophy as it is taught in most English-speaking universities, and as I believe it should be taught. The answer is best given by recording a conversation I had with the late Professor H.M. Sheffer of Harvard, whom I met there towards the end of the war when I was working at the British Embassy in Washington. Sheffer, one of the most eminent mathematical logicians of his day, said to me that in his opinion there were only two philosophical disciplines in which one could hope for an increase of permanent knowledge : one was logic, in which new discoveries and techniques superseded the old ones - this was a field of exact knowledge in which genuine progress occurred, as it dit in the natural sciences or mathematics ; the other was psychology, which he thought of as being in some respects still philosophical - this was an empirical study and obviously capable of steady development. And, of course, there was the history of philosophy itself ; as for logic and psychology, they differed from philosophy proper, to which - unlike history or classical learning - the notion of growth, of cumulative knowledge, did not seem to him to apply. " To speak of a man learned in epistemology, or a scholar in ethics, " he said "does not make sense ; it is not that kind of study." He went on to say that philosophy was a marvellous province of thought, but it had not been helped, in his view, indeed had been gravely damaged, by what logical positivists, influenced by symbolic logicians like himself, were now doing ; the kind of work that "Carnap and Co." (as he called them) were engaged upon repelled him - it would ruin real philosophy as he and his master Royce conceived it : " If any work of mine has done anything to stimulate this development, I had rather not have been born." Although I did not, and do not, agree with Sheffer's to the sweeping condemnation of the value and influence of logical positivism, or the rigid division he drew, repudiating his own earlier views, between logic and philosophy, his words made a profound impression upon me. In he months that followed, I asked myself whether I wished to devote the rest of my life to a study, however fascinating and important in itself, which, transforming as its achievements undoubtedly were, would not, any more than criticism or poetry, add to the store of positive human knowledge. I gradually came to the conclusion that I should prefer a field in which one could hope to know more at the end of one's life than when one had begun ; and so I left philosophy for the field of the history of ideas, which had for many years been of absorbing interest to me."