Abstract

The question of how physicalism originated is a complex one, to which we cannot expect an unambiguous answer. The major reason for this is that there were different formulations of the doctrine, which makes it near impossible to identify the inventor of physicalism. Nonetheless, the received view is that the main actors were Neurath and Carnap: Neurath proposed his versions of physicalism earlier, but it was Carnap who first published an elaborated formulation of the metalinguistic doctrine according to which the universal language of science ought to be physical language. However, in 1932 Wittgenstein accused Carnap of plagiarism concerning physicalism (ignoring Neurath's contributions completely). There is considerable literature on the origins of physicalism as well as on the priority-dispute between Wittgenstein and Carnap. The aim of my paper is to contribute to these investigations. However, I look at the topic from a somewhat different angle, in the following regard. Examinations of the diverse early physicalist doctrines as well as of the priority claims concerning physicalism tended to focus on the accounts of “primary language” or “protocol language”; on whether observation sentences ought to be formulated in phenomenalistic or physicalistic language, referring to experiences or to physical objects and their properties. In contrast, I concentrate on Carnap's and Wittgenstein's views on the content of psychological sentences, in particular heteropsychological sentences, which report the psychological states of other persons. Carnap and Wittgenstein both proposed physicalistic-behaviouristic accounts starting in the late 1920s. I examine in detail Carnap’s and Wittgenstein’s accounts between 1929 and 1932, their connections, and the arguments put forward in favour of them. Presenting their rather similar views as well as their rather different motivations and background assumptions casts further light on the emergence of physicalism in the early thirties, and possibly also on Wittgenstein's troubled relationship with Carnap.