Editorial Note PIERO SRAFFA who passed away at Cambridge recently, was a truly outstanding intellectual figure of our times. A student of Achille Lori, for whom he scarcely had much sympathy, he was drawn to Marxism and developed a deep friendship with Antonio Gramsci in his Turin days, which was to last until the very end of Gramsci's life. He was one of the very few regular visitors of Gramsci in prison. and remained, in the words of Gramsci5 s biographer Fiori, "his devoted friend through all his years of suffering". It was with Grams ci's approval and encouragement that he took upon himself the gigantic task of editing the complete works and correspondence of David Ricardo; this task occupied him till the end of his active life at Cambridge, where he was brought by Tohn Maynard Keynes from Mussolini's Italy. The outlines of his famous critique of neo-classical economics, published in 1960 under the title Production of Commodities by Means of Commodities, had already been devloped by him in the 1920's and can be discerned in his Introduction to the first volume of Ricardo's Works. This critique showed up the complete logical untenability of the bulk of post-classical bourgeois economics and validated Ricardo's proposition, shared by Marx, that prices of production are formed only on the basis of a given social distribution of income. It re-established, in other words, the validity of the rate of exploitation as being logically prior to the determination of the prices of production. It followed from the critique that underlying class distribution of income were socio" historical elements like relative class strengths rather than any "marginal productivities of factors of production" as modern bourgeois economics had asserted. While at Cambridge, Sraffa formed another close friendship, this time with Ludwig Wittgenstein with whom he shared lodgings for a while. Sraffa's persistent criticism was one of the main reasons behind Wittgenstein's transition from the positions he had taken in his Tractatus Logicio-Philosphicus to those of his Philosophical Investigations. As Wittgenstein himself was to acknowledge in his preface to Investigations, he was indebted to the stimulus of Sraffa's criticism "for the m'ost consequential ideas of this book". The full meaning and implications of Sraffa3 s theoretical work are far from clear as yet. For one thing, he published very little, of which the output in English is even less. Besides, he was extermely reticent about discussing his own work. His standard reply to questions about the relationship of his work to Marx's value theory, a subject which aroused, often to his anguish, much controversy, was: "You