tautien

Tautien is a neologism used in speculative philosophy and science fiction to refer to a hypothetical property of a language, knowledge system, or formal theory in which its truths are closed under a certain class of self-evident inferences. In such a system, statements derive from a minimal base through tautological or universally valid rules, producing a state of maximal logical coherence where no new, contingent assumptions are required to validate accepted claims.

The term has no standardized formal definition; its meaning varies by author. Generally, it suggests resilience to contradiction when the base of axioms is extended and a tendency toward redundancy, in which added rules do not alter what is already entailed.

In practice, tautien is mainly used as a thought experiment. Writers employ it to examine what a perfectly coherent language would imply for meaning, translation, and knowledge representation, and to test boundaries between semantic clarity and informational content.

Critics argue that tautien risks degenerating into semantic triviality or an unattainable ideal, because any nontrivial system requires contingent assumptions, and a truly tautien-like state may be incompatible with expressive power or empirical content.

See also: tautology, formal language, axiom system, self-reference, philosophy of language, logic.