Abstract

Ajdukiewicz’s the project of semantic theory of knowledge comes down to the statement that reflection upon logically understood concepts and judgments—which constitute the logically understood knowledge—is equivalent to the reflection upon terms and sentences whose meanings are those concepts and judgments. The value of this equivalence lies in the fact that it allows to apply the results obtained in metamathematics, treating of expressions and sentences, to epistemology, which pursuant to the mentioned equivalence is also treating of expressions and sentences, and which—similarly to mathematics—is also a metatheoretical discipline. What is more, this equivalence allows to maintain the connection of semantic theory of knowledge, that speaks about expressions and sentences, with traditional theory of knowledge, that speaks about concept and judgments understood in a logical way.This equivalence was justified by Ajdukiewicz. Yet in his justification he did not refer to any philosophy of a language, including the philosophy of language and knowledge. Not every philosophy of language is a philosophical language reason of this justification, that is not every philosophy of language is a philosophical language justification of this justification. The one which is appropriate for this project is, in my opinion, Edmund Husserl’s intentional theory of expressions from his Logical investigations. Indicating the appropriateness of this philosophy of language for this project is the main task which I undertake in this paper.