In this part of my study, I turn to Heidegger's philosophy.¹ I shall try to establish that, except for his very early writings, Heidegger's ideas on language, truth, semantics, and logic are naturally interpreted as just so many corollaries of his belief in language as the universal medium. The position that Heidegger eventually developed thus shows a marked contrast to Husserl's and to that of most of contemporary analytical philosophy. As we shall see below, however, even the Heidegger of the later writings does not stand completely isolated among his colleagues of this century. Several tenets of his later thought bear a remarkable resemblance to ideas proposed by Ludwig Wittgenstein. I shall point out some of these parallels, notwithstanding that comparisons between Heidegger and Wittgenstein have already been presented by other interpreters. A new examination of the parallels between Wittgenstein and Heidegger seems to be called for by recent advances in Wittgenstein scholarship. Notably, the book by Merrill B. and Jaakko Hintikka on Wittgenstein's universal medium conception² provides a whole variety of new insights that have not yet been exploited in Heidegger research.