Tautology, in logic, a statement so framed that it cannot be denied without inconsistency. The notion was first developed in the early 20th century by the American philosopher Charles Sanders Peirce, and the term itself was introduced by the Austrian-born British philosopher Ludwig Wittgenstein. Tautology is the needless repetition of a single concept. In other words, it is saying the same thing twice in different words. The following are examples of tautology: a single bachelor, PIN number, ATM machine. Tautology, as a literary device, is a repetitive use of phrases or words which have similar meanings used for emphasis or poetic license. Learn what a tautology is in Maths, how to identify it using truth tables and logical symbols, and how it differs from a contradiction. A tautology is a compound statement that is always true for any value of the simple statements.
