1 ERNST MACH AND THE ELIMINATION OF SUBJECTIVITY 1. The neutrality of the given ...one of the greatest advantages and attractions of true positivism seems to me to be the antisolipsistic attitude which characterizes it from the very beginning...perhaps the philosophy of Mach and Avenarius [is] one of the most consistent attempts to avoid [solipsism]... ...primitive experience is absolutely neutral...To see that primitive experience is not first-person experience seems to me to be one of the most important steps which philosophy must take towards the clarification of its deepest problems. These quotations - from Schlick's late article "Meaning and Verification" (1936) - illustrate the constant positivist desire to eliminate the subject, to transcend subjectivity.1 This ostensibly anti-solipsistic "neutralism" was, as Schlick records, expressed earlier in the "neutral monist" philosophy of his predecessor as Professor of the History and Philosophy of the Inductive Sciences at Vienna, Ernst Mach. The present article is the first of two, concerned to explain the development and influence of this aspect of positivist "neutralism" from Mach to the Vienna Circle. "Neutral monism" has the unexciting sound of a long-forgotten doctrine, redolent of the casuistry of dusty old volumes. It is however probably the most economical label for the influential standpoint presented by Mach in The Analysis of Sensations - a strangely potent doctrine in the fin de siecle philosophical milieu. Neutral monism expresses what Schlick termed the "immanence standpoint". That is, it equates the real with what is "given" in experience - "a realm standing above all doubt".2 But the given, though not yet considered mythical, was not to be construed as given to someone. "Experience" was essentially subjectless. In marked contrast to earlier positivists such as Comte, Helmholtz and Spencer, Mach and his followers were united by a hostility to representative realism and the veil of perception, and sought to eliminate both the subject to whom perceptions were given and the things-in-themselves that were the unperceived causes of those perceptions. Neutral monism was advocated by a number of Mach's contemporaries, of whom the most notable was Richard Avenarius. With its desire for a wholly pre- theoretical point of departure in philosophy, a subjectless "given" with minimal additions on the part of "thought", the doctrine contributed to a new, "critical" trend in German positivism.3 It became a constant theme in the work of positivists up to the time of the Vienna Circle; it was also adopted by figures of different traditions such as William James and, for a time, Bertrand Russell.4 Mach anticipated the non-sceptical solipsism of Schlick, Carnap and Wittgenstein. Complementary to this, he advocated a precursor of 20th-century linguistic phenomenalism, influencing inter alia the conventionalist constructionalism of Carnap's Aufbau. His neutral monism initiated an unstable transitional phase in the history of empiricism. Taking the subjectless "given" as a starting-point in philosophy is, historically, mid-way between starting with a subjective "given" (the empiricist assumption until the later 19th century), and not starting with a "given" at all (empiricism self-destructs in post-Quinean naturalism).5 This "neutralist" standpoint was to receive its most sophisticated expression in the work of the Vienna Circle. 2. Mach's atomism Ernst Mach is the Douanier Rousseau of modern philosophy. He exercised a remarkable philosophical influence in the Viennese milieu, one which is surprising since he was primarily a scientist, a self-confessed philosophical ingenu whose important writings in the central areas of the subject were