This study identifies a line of continuity through Wittgenstein s Philosophy based on his distinction between the necessary and the contingent domains of language. This distinction is concerned with the impredicativity featured by the necessary domain. This continuity is particularly evident in Wittgenstein s Philosophy of Mathematics. My thesis claims that the consequences of this continuity in the treatment of the necessary domain of language are permanently developed throughout his work. First, I present the impredicativity notion roots in the systems of Poincaré and Russell. As of this, I evaluate also this notion importance to the beginning of Wittgenstein’s Philosophy and to his criticism about Russell’s approach to a Theory of Types. Thereafter, I discuss the impredicativy importance to the turn of Wittgenstein’s thought in its intermediary period as well as to his positions about the mathematical truth and demonstrations. This study contains also an appendix in which I apply the proposed interpretation to the comprehension of Wittgenstein’s remarks on Gödel incompleteness theorem. The thesis main contribution is to offer an alternative interpretation of Wittgenstein s Philosophy conveying unity, systematization and an internal coherence to his most awkward and strangest positions. Moreover, since it is assumed that the necessary field of language is responsible for the linguistic meaning determination, the impredicative feature in the semantic determination is highlighted. As a result, this feature must be assumed not only as an approach to Wittgenstein s Philosophy, but also by everyone that is concerned with the general problem of meaning and with its consequences to a semantic justification to mathematical constructivism.