ЛОГИЧЕСКАЯ И ФАКТИЧЕСКАЯ ИСТИНА

Logical and Factual Truth

Logical concepts dating from Leibniz, who distinguished between necessary truth, or "truths of reason", and incidental truths, or "truths of fact". The truth of the former is derived from the laws of logic, the truth of the latter, from correspondence with the actual state of affairs. Leibniz, who regarded the laws of logic as absolute, held that "truths of reason" are true in all possible worlds (i.e., worlds that are not contradictory to logic), whereas truths of fact are true only in some worlds (including the world we live in).

A similar distinction was made by Hume and Kant (see Synthetic and Analytic). Modern logic maintains this distinction without regarding it as absolute. Thus, the Carnap-Kemeny logical semantics considers statements to be logically true that are true in all admissible interpretations (see Interpretation and Model) of the given formalized language, while statements that are true in a particular interpretation but not in all admissible interpretations are only factually true.