Tautology
noun /tɔːˈtɒlədʒi/ — Saying the same thing twice and calling it an argument.
Definition
The saying of the same thing twice in different words; in logic, a statement that is true in every possible interpretation — and therefore tells you nothing.
Beyond the definition
Recognizing a tautology is one of the more satisfying moments in critical thinking. 'It's true because it's true.' 'What will be will be.' 'The best person won because winning makes you the best.' Once you learn the word, you see tautologies everywhere — in politics, in self-help, in everyday justifications that loop back on themselves.
Origin & history
From Greek tautologia — 'saying the same thing', from tauto 'the same' + logos 'word'. Aristotle used it critically to describe arguments that assume what they're supposed to prove.
Example sentences
Illustrative sentences for learning, not verified community posts or sourced quotations.
His defense was circular — pure tautology dressed up as reasoning.
'Love is love' works as a political slogan precisely because its tautology is its point.
Spotting the tautology in an argument is often the fastest way to end it.
How to use it
This entry uses a noun. Follow the examples for articles and singular or plural forms; not every noun takes “a” or “an.”
Choose “Tautology” when the meaning fits your context: The saying of the same thing twice in different words; in logic, a statement that is true in every possible interpretation — and therefore tells you nothing.
Synonyms
repetition, circularity, redundancy, pleonasm
Antonyms
novel insight, informative statement, substantive claim
Related words
Tautology vs pleonasm
Tautology involves repeating the same idea in different words. Pleonasm specifically refers to the use of extra, redundant words that add no meaning to the phrase.
Word in the Wild
See how this word appears in life, language and stories.
Illustrative sentences and imagined stories for learning — not verified sightings, interviews, or sourced quotations.
Fictional scene
Closed Circular Logic
A speaker stands before a mirror, repeating the same gesture and expression, creating a visual loop that never expands or changes.
A tautology is a statement or logic that is true in every interpretation and thus conveys no new information. The mirror loop visually captures the essence of a circular argument where the start and end points are identical, confirming nothing.
Image credit: Wordspun · AI-generated conceptual illustration
Questions about this word
What does "Tautology" mean?
Tautology is noun meaning: Saying the same thing twice and calling it an argument.. The saying of the same thing twice in different words; in logic, a statement that is true in every possible interpretation — and therefore tells you nothing.
Where does the word "Tautology" come from?
From Greek tautologia — 'saying the same thing', from tauto 'the same' + logos 'word'. Aristotle used it critically to describe arguments that assume what they're supposed to prove.