Bivalence and Determinism: Real or Pseudo-Problem? Łukasiewicz’s Reconstruction of an Ancient Debate

Jan Łukasiewicz, in a series of writings from 1918 to 1946, argued against logical determinism-the idea that the truth or falsity of a statement predetermines future events, thus limiting free will. To defend an indeterministic worldview, he rejected the principle of bivalence and introduced a third value, the ‘indeterminate’, pioneering polyvalent logics. This problem dates back to Aristotle's De interpretatione and the Hellenistic disputes involving Stoics, Epicureans, and Academics. As an expert historian of ancient logic, Łukasiewicz was well acquainted with these debates and employed classical patterns of reasoning in his argument. However, while Łukasiewicz believed that classical logic entails determinism, the author of this text claims that bivalence has no bearing on free will. He argues that the problem arises from a failure to distinguish between different types of truth-bearers (propositions, sentences, assertions) and from a conceptual confusion between causality and logical implication, as Gilbert Ryle pointed out. The author concludes that logical determinism is ultimately a pseudo-problem that has persisted for centuries due to a lack of clear definitions of the key concepts involved in it.