Philosophical Motivations of Jan Łukasiewicz’s Three-valued Logic

Abstract

The paper seeks to reconstruct the philosophical genesis of Jan Łukasiewicz’s three-valued logic. The assumptions that have explicitly been given by Łukasiewicz have been supplemented by the author’s hypotheses, put forward on the basis of the logician’s works. It has turned out that a rich and complicated structure of ontological, semiotic, and metascientific statements make up that system. Owing to incoherence of some of them, however, they cannot play the role of being a reason for logic Ł3.