Piero Sraffa

Piero Sraffa (1898-1983) was an Italian economist from Turin and a close friend of the Marxist thinker Antonio Gramsci. He fell foul of Mussolini and moved to Cambridge in 1927, with help from John Maynard Keynes. When Wittgenstein returned to Cambridge in 1929, the two began talking, often once a week, for well over a decade. Sraffa published almost nothing on philosophy. Yet in the preface to the Philosophical Investigations Wittgenstein names only two critics: Frank Ramsey and Sraffa, to whose criticism he says he owes the most consequential ideas of the book.

The gesture

The best-known story comes from Norman Malcolm's memoir of 1958. Wittgenstein was insisting that a proposition and what it describes must have the same logical form. Sraffa brushed his fingertips outward under his chin, a Neapolitan gesture of disdain, and asked: what is the logical form of that? According to Malcolm, the exchange broke the hold on Wittgenstein of the idea that a proposition must literally be a picture of the reality it describes. The real development was slower and messier than the anecdote, but it captures the point. A gesture means something, and its meaning lies in a way of life, not in a shared logical skeleton.

What Wittgenstein took from Sraffa

Wittgenstein told Rush Rhees that Sraffa taught him an "anthropological" way of looking at philosophical problems. Instead of asking what structure language must have, you look at what people actually do with words, within a community and its customs. That is the soil in which language games and forms of life grow. What exactly the word "anthropological" meant is open to interpretation. Amartya Sen, in a 2003 essay on Sraffa, Wittgenstein and Gramsci, reads it as a recognition that thought and meaning depend on social conventions. Others link it to the style of Sraffa's economics.

What Sraffa did with it, and where they differed

The traffic ran mostly one way. Sraffa's own masterpiece, Production of Commodities by Means of Commodities (1960), is a terse economic model, not a philosophical book. Some readers see a family likeness in it: like the later Wittgenstein, Sraffa avoids hidden essences and works from observable relations between things. The friendship had limits too. In 1946 Sraffa ended the regular conversations, saying he no longer wanted to give his time to the questions Wittgenstein cared about. For the story in detail, see the overview by the Wittgenstein Archives at Bergen and Sraffa's profile at Trinity College.