The expression "raze to the ground" is a tautology, since the word "raze" includes the notion "to the ground".
Given a Boolean A, "A OR (NOT A)" is a tautology.
A logical statement which is neither a tautology nor a contradiction is a contingency.
A tautology can be verified by constructing a truth tree for its negation: if all of the leaf nodes of such truth tree end in X's, then the original (pre-negated) formula is a tautology.
The statement "the reason is because" is an example of a tautology because "the reason" and "because" are essentially the same thing said twice in different ways.
The statement "it is either right or it is left" is an example of a tautology because the statement by definition always has to be true.
Other Word Forms
Origin of tautology
- Late Latin tautologia from Greek tautologiā from tautologos redundant tauto- tauto- logos saying –logy
From American Heritage Dictionary of the English Language, 5th Edition
- From Late Latin tautologia, from Ancient Greek ταυτολογία (tautología) from ταὐτός (tautós, “the same") + λόγος (lógos, “explanation")