In 1930, Moritz Schlick, the unofficial leader of the Vienna Circle, published in the first number of their journal a short paper entitled "Die Wende der Philosophie" (Turning-point in philosophy).¹ Yet another important turning point in philosophy had taken place in the same locale in 1928–29 when Ludwig Wittgenstein had begun to move away from the ideas of his Tractatus Logico-Philosophicus. In this paper, I shall be dealing with the latter turning-point, not the self-advertised Wende der Philosophie of the Vienna Circle.