Is anything known about the content of Sraffa's critique of Wittgenstein's Philosophy?

Question

in the preface to Wittgensteins Philosophical Investigations he says:

For since beginning to occupy myself with philosophy sixteen years ago I have been forced to recognise grave mistakes in what I wrote in that first book; I was helped to realise these mistakes to a degree that I can hardly estimate by the criticism ... Of Frank Ramsey; ...[and] even more than this, by the always forcible and certain criticism ... Of Mr P Sraffa [who] for many years unceasingly practised on my thoughts.

Is there any indication on the Investigations itself, or in the philosophical literature, or indeed in Sraffas what the content of this critique could be? Or would it, at best, remain educated and informed guess-work?

Answer 1

Despite research that was done, and the availability of the Wittgenstein-Sraffa correspondence, there seems to be no evidence for a specific philosophical influence on Sraffa on Wittgenstein. The short essay "Sraffa’s Impact on Wittgenstein" (Matthias Unterhuber, 2013) summarizes the currently available evidence on the subject.

The most famous story regarding Sraffa and Wittgenstein, concerning a certain gesture made by Sraffa, while riding on a train with Wittgenstein, was told by Norman Malcolm:

Wittgenstein was insisting that a proposition and that which it describes must have the same 'logical form', the same 'logical multiplicity'. Sraffa made a gesture, familiar to Neapolitans as meaning something like disgust or contempt, of brushing the underneath of his chin with an outward sweep of the finger-tips of one hand. And he asked: 'What is the logical form of that?'

Sraffa's gesture is said to have made a profound impression on Wittgenstein. Still, the details of this incident, and its interpretation, are in much dispute.

Sraffa was not a philosopher, but an economist. He didn't publish anything on philosophy, or on Wittgenstein.

The most plausible conclusion seems to me, that Sraffa influenced Wittgenstein by being for him a model of an intelligent person without philosophical training. Wittgenstein came to appreciate and to take into consideration Sraffa's raw pre-philosophical intuitions. Although there is no known direct link between Sraffa and any specific assertion or argument in Wittgenstein's texts.

Answer 2

Among Straffa's you will find two different types of texts, comments and notations. Unfortunately I could not find the quotes but here are some comments.

1. You say: circumstances. Why always torn out or made up phrases? Why don’t you take them from the works of some phil[osophers]
2. Cause. Is it, historically, true?
3. Remedy. Does it in fact cure?
4. Metaphysics, why not theology?
5. Psycho-An[alysis], dispute

Hope this helps