The non-classical thesis concerning entailment that a proposition can never entail its own negation. In systems with a negation connective and conditional connective , this is made formal by accepting the axiom
The thesis is named after Aristotle (384–322 bce), who asserts in the Prior Analytics that it is impossible that the non-greatness of an object entails its greatness. Aristotle’s thesis is one of the hallmarks of connexive logics.