The question is raised of the source of the extreme verificationist views which Wittgenstein put forward immediately after his return to philosophy in 1929. Since these views appear to be radically different from the ideas put forward in theTractatus some explanation of this dramatic new turn in Wittgenstein''s thought certainly seems to be called for. Wittgenstein''s very low level of interest in philosophy between 1918 and shortly before his return to philosophy is documented. Attention then focuses on the crucial period (...) immediately before Wittgenstein''s return to Cambridge, and it is shown that in this period he encountered only two new philosophical influences. These were the ideas of Brouwer and the ideas of the Vienna Circle. Each of these is examined and neither is found capable of providing an explanation of the source of Wittgenstein''s verificationism. This leads to a reconsideration of the underlying assumption that Wittgenstein''s verificationism does represent the radical departure from the ideas of theTractatus which it appears to. It is argued that the only way we can account for Wittgenstein''s evident approval of the reading of theTractatus which he must have encountered in his meetings with members of the Vienna Circle is by concluding that, far from being incompatible with his earlier ideas, some form of verificationism must always have been implicit in theTractatus. (shrink)