フレーゲ論理哲学的探究の認識論的位相とメタ理論の可能性

Abstract

First I will characterize Frege's "logicism" epistemologically. His "logicism" is originated from his epistemological claim of the "analyticity" of arithmetic. In order to confirm this, it needs to show that any arithmetic proposition is derivable from the logical laws with the logical definitions alone. Nevertheless there was no such powerful logic in the 19th century, and so Frege was forced to invent the radically new logic.Further Frege understands inferences and judgments epistemologically. He construes an inference as justifying a conclusion based on its premises, and both premises and conclusion as assertions/judgments, which Frege takes as holding true, whereas he regards the justified conclusion as recognition of its truth (knowledge).Frege's "sense" is not only the contribution to the truth-condition, but is also related to the cognitive value of a proposition, to the modes of presentation of the designation, and to various propositional attitudes, as is well known.Second I expound Fregean semantic explanations of logic, and mention Fregean meta-theoretic proof of independence briefly.