Frege – Schlick -Wittgenstein: Family Resemblances in their Philosophizing on Logic

Title: Frege – Schlick – Wittgenstein: Family Resemblances in their Philosophizing on Logic

Ingolf Max

Gottlob Frege (1848 – 1925) is not only considered one of the founding fathers of modern logic, but also a cofounder of contemporary analytic philosophy. His philosophizing about logic was directly linked to the motivation of undefinable basic concepts in the course of his invention of 3 a “Begriffsschrift, a Formula Language, Modeled Upon That of Arithmetic, for Pure Thought”, which we now call “classical logic”. Moritz Schlick (1882 – 1936), the integrating figure of the Vienna Circle, moved from physics to philosophy which he characterizes sometimes “consequent empirism”. His understanding of logic was initially limited to Aristotelian syllogistic. Under the lasting influence of Wittgenstein's “Tractatus logico- philosophicus”, he acquired a sound knowledge of Fregean and Russellian logic. But he was never a logician like Frege. His philosophizing remained mainly oriented towards sciences, ethics, culture and art. Ludwig Wittgenstein (1889 – 1951) used modern logic for his early project to determine the limits of the world from a pure internal point of view. Later he considered logic more and more in the context of the grammar of colloquial language, but without striving for a theory of language. There is a problematic tendency to split analytic philosophy into ideal and natural language philosophy. But on closer inspection we see that this picture is not only far too simplistic, but also misleading. Given the different philosophical interests of Frege, Schlick, and Wittgenstein, we will highlight some similarities and differences in their perspectives on logic. We paint a much more complex picture of family resemblances that leads us to understand the importance of philosophizing before, with and ab out logic, even if it will lead us neither to an ultimate philosophy of logic nor to THE logic in the sense of a formal theory.