- 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.
- needless repetition of an idea in different words; redundancy; pleonasm (Ex.: “necessary essentials”)
- an instance of such repetition
- Logic a proposition that is analytic (sense )
Origin of tautologyLate Latin tautologia ; from Gr: see tauto- and amp; -logy
- a. Needless repetition of the same sense in different words; redundancy.b. An instance of such repetition.
- Logic An empty or vacuous statement composed of simpler statements in a fashion that makes it logically true whether the simpler statements are factually true or false; for example, the statement Either it will rain tomorrow or it will not rain tomorrow.
Origin of tautologyLate Latin tautologia, from Greek tautologia, from tautologos, redundant : tauto-, tauto- + logos, saying; see –logy.
- tau′to·log′i·cal , tau′to·log′ic , tau·tol′o·gous
- tau′to·log′i·cal·ly, tau·tol′o·gous·ly
(countable and uncountable, plural tautologies)
- (uncountable) redundant use of words
- It is tautology to say, "Forward Planning".
- (countable) An expression that features tautology.
- The expression "raze to the ground" is a tautology, since the word "raze" includes the notion "to the ground".
- (countable, logic) A statement that is true for all values of its variables
- 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.
From Late Latin tautologia, from Ancient Greek Ï„Î±Ï…Ï„Î¿Î»Î¿Î³Î¯Î± (tautologÃa) from Ï„Î±á½Ï„ÏŒÏ‚ (tautÃ³s, “the same") + Î»ÏŒÎ³Î¿Ï‚ (lÃ³gos, “explanation")