John Forrester: What Freud, Einstein and Wittgenstein thought about the truth of psychoanalysis

From the inaugural lecture of the Cambridge professor of history and philosophy of the sciences on the reception given to Freud's thought at Cambridge University in the 20th century

In Cambridge, psychoanalytic enthusiasm was very high from the 1920s, when the psychoanalytic field was open to any scientist or philosopher with enthusiasm and commitment; and when psychoanalysis was viewed as a potentially life-transforming experience. Geophysicist, logician, all-purpose tinkerer, worldly economist – discipline was no bar to engagement and innovation in psychoanalytic matters.

Freud was undoubtedly the presiding spirit for these men. John Maynard Keynes judged him "a sort of devil" for the times, just as WH Auden would in 1939 name him as a climate of opinion. But the enthusiasm did not lead to the founding of the Psychoanalytic Tripos which Lionel Penrose had assumed he would find when he came up to St John's College in 1919. Where would psychoanalysis belong? Every plausible location is equally implausible. An essential part of the modern education, but with nowhere in Cambridge that it calls a home – this is something I am acutely aware of, because since 1974 I have taught for 14 out of the 21 faculties in this university.

How appropriate and generous, then, that I take up this personal chair in the Department of History and Philosophy of Science, which is the institution in this university most open to varied currents of thought and enquiry, extending from the Ancient Greeks to the philosophy of mathematics, from the architecture and geography of the laboratory to the contemporary use of placebos in medicine.

I close with the scene depicted in the delightful poster announcing this lecture: Einstein on Freud's couch. In 1936, Einstein wrote to Freud:

"Until recently I could only apprehend the speculative power of your train of thought without being in a position to form a definite opinion about the amount of truth it contains. Not long ago, I had the opportunity of hearing about a few instances which in my judgement exclude any other interpretation than that provided by the theory of repression. I was delighted to come across them; since it is always delightful when a great and beautiful conception proves to be consonant with reality."

Like all history, this letter conceals more than it reveals. We do not know what the few instances were, nor are we ever likely to know. Freud's reply put Einstein on the spot:

"Of course I always knew that you 'admired' me only out of politeness and believed very little of any of my doctrines, although I have often asked myself what indeed there is to be admired in them if they are not true, i.e. if they do not contain a large measure of truth. By the way, don't you think that I should have been better treated if my doctrines had contained a greater percentage of error and craziness?"

Perhaps the last word on the question Freud throws back to Einstein should go to that other strange visitor from Vienna, Wittgenstein, whose preoccupation with Freud was pretty much a lifelong affair, writing to Norman Malcolm in 1945:

"I, too, was greatly impressed when I first read Freud. He's extraordinary. Of course, he is full of fishy thinking & his charm & the charm of his subject is so great that you may be easily fooled. He always stresses what great forces in the mind, what strong prejudices work against the idea of psycho-analysis. But he never says what an enormous charm that idea has for people, just as it has for Freud himself. There may be strong prejudices against uncovering something nasty, but sometimes it is infinitely more attractive than it is repulsive."

How are we to arm ourselves against the attractions of the repulsive? Shouldn't we recognise that Freud's version of enlightenment is that of the candle to which we respond in the manner of moths?

His warning tone did not prevent Wittgenstein adding: "All this, of course, doesn't detract from Freud's extraordinary scientific achievement. Only, extraordinary scientific achievements have a way these days of being used for the destruction of human beings. So hold on to your brains."

"Hold on to your brains." That, after all, is a very Cambridge response to Freud.