A key problem to be faced in the interpretation of any philosophical position concerns its essential continuity or discontinuity over time. There is, of course, no single way of responding to this concern. One kind of strategy, which in principle seems to me to be nearly as misguided as it is frequently employed, consists in the emphasis on discontinuity. It is this kind of approach which elsewhere in the literature has given rise to interpretative anomalies, in which different positions are allegedly distinguished within a single philosophical corpus, such as Wittgenstein I and Wittgenstein II, early Marx the philosopher and late Marx the economist, Heidegger before and after the Kehre, and the four phases of Russell's thought as radically distinct but closely related to his different marriages.