Logical Determinacy versus Logical Contingency. The Case of Łukasiewicz’s Three-valued Logic

Abstract

In constructing the three-valued logic, Jan Łukasiewicz was highly inspirited by the Aristotelian idea of logical contingency. Nevertheless, we can construct a four-valued logic for explicating the Stoic idea of logical determinacy. In this system, we have the following truth values: 0 (‘possibly false), 1 (‘necessarily false’), 2 (‘possibly true’), 3 (‘necessarily true’), where the designated truth value is represented by the two values: 2 and 3.

Keywords

• łukasiewicz
• many-valued logic
• three-valued logic
• modal logic
• four-value logic
• logical contingency
• logical determinacy