Tautology is the unnecessary repetition of the same idea using different terms. It is applied to language and writing standards as something to be avoided in formal writing.
Tautology is a redundancy, like the expression "vicious circle". If it is circular, it is evident that it must go back to the starting point, and therefore it repeats itself as something vicious, being unnecessary to use the other term to define it.
It is also called vicious pleasmus as a figure of speech.
Learn more about the meaning of pleonasm.
The word tautology comes from the Greek tautologers, which joins the terms tautos, which means same or identical, and logos, which is word, or what was said.
Tautology is also used in philosophical rhetoric when the same argument is used repeatedly in the manifestation of thought.
Examples of Tautology
- Link - The link here is unnecessary, as the word link alone presupposes the existence of a relationship.
- unexpected surprise - Every surprise is unexpected, otherwise it would not be a surprise.
- face to face - to face is already to be ahead, face to face.
- years ago - the use of "ha" already demarcates that it is a past tense, not being necessary to include the "behind".
- expressly prohibited - if it is prohibited, there is no way to allow it. Porting the "expressly" to demarcate the mode is not necessary.
- temporary loan - if it is borrowed, it already demonstrates that it is not definitive, otherwise it would be given and not borrowed.
Tautology in Mathematics
Tautology is also a concept of logical-mathematical reasoning, composing the so-called compound prepositions, formed by tautology, contradiction and contingency.
It is a tautological proposition that always assumes the true logical value (V)
The so-called contradictions are propositions that assume the false value (F). Whereas contingencies, or indeterminate propositions, are those that are neither tautological nor contradictory.