Introduction

Alessandro Roncaglia in his book Sraffa e la teoria deiprezzi (1975), an English version of which was published as Sraffa and the Theory of Prices (1978), put forward the view that Sraffa’s systems of price equations are best interpreted in terms of a “photograph” taken of the economic system at a given moment of time or, rather, a snapshot of a cycle of production of the system.

The determination of prices was studied at a given moment of time, given the prevailing technology. [...] In other words, the classical economists’ analysis of prices examined the situation of a given economic system at a given moment in time, much like a photograph of the system at an instant in time.

He added,

In this way all the economic variables which were not the object of analysis could be con­sidered as given. Theoretical investigation could concentrate attention on the “virtual” movement of specific variables and on the relations between these variables as if they were being considered “isolated in a vacuum.” In the case of Production of Commodities by Means of Commodities the choice of variables to be analysed has fallen on the relations that exist between prices of production and the distributive variables, the wage rate and the rate of profits. (Roncaglia, 1978, 21)¹

This short contribution revolves around the metaphor of “photograph” and its possi­ble meaning(s) in Sraffa’s preparatory papers leading up to his 1960 book and the book itself. We proceed in the following way. We ask, first, whether, and if so, when Sraffa came across the metaphor in the literature and used it himself (section 2). Next we draw the attention to another, but closely related, metaphor Sraffa used: “the man from the moon,” and its possible relation to David Ricardo’s activities in Parliament (section 3). Then we discuss a statement by Maffeo Pantaleoni in one of his books that Sraffa annotated. His annotations throw some light on the materialist or objectivist approach Sraffa was keen to develop in the late 1920s and at the beginning of the 1930s (section 4). Then we reflect upon the relationship between Sraffa’s analysis in his 1960 book and what he called “the standpoint [...] of the old classical economists from Adam Smith to Ricardo” (1960, v) in the theory of value and distribution (section 5). The met­aphor of the photograph reappears in Sraffa’s correspondence with a German student in 1968, and its meaning there is precisely the one implied by Sraffa’s characterization of the classical as opposed to the marginalist approach in the theory of value and distri­bution. The way Roncaglia uses it is similar (section 6). The paper concludes with a few final observations (section 7).

2.