ταυτολογία

Tautología in Greek combines tauto ('the same') and logos ('speech' or 'reason'). The rhetorician's meaning came first: saying the same thing in different words. 'Free gift.' 'Past history.' 'Close proximity.' Aristotle noted tautology as a rhetorical fault in his Rhetoric — repetition that adds nothing. It was a failure of precision, a sign that the speaker had run out of ideas.

Medieval Latin inherited tautologia as a term for redundant expression. Grammarians catalogued tautologies alongside pleonasms and other stylistic sins. The word carried a consistent judgment: if you are saying the same thing twice, you are wasting everyone's time. Tautology was intellectual laziness dressed in extra syllables.

Then Ludwig Wittgenstein and the logical positivists of the early 1900s gave the word a second, almost opposite meaning. In formal logic, a tautology is a statement that is true by its own structure — 'Either it is raining or it is not raining.' Such statements carry no empirical information, but they are not redundant in the rhetorical sense. They reveal the architecture of logic itself. Wittgenstein called them 'senseless' but not 'nonsensical.'

English now uses tautology in both senses, and they often collide. A politician accused of tautology might be committing a rhetorical sin or stating a logical truth — the accusation itself is ambiguous. The word carries two thousand years of arguments about the difference between saying nothing and saying something necessarily true.