4.46 Among the possible groups of truth-conditions there are two extreme cases. In the one case the proposition is true for all the truth-possibilities of the elementary propositions. We say that the truth-conditions are tautological. In the second case the proposition is false for all the truth-possibilities. The truth-conditions are self-contradictory. In the first case we call the proposition a tautology, in the second case a contradiction.
Tautological
