Tautology (logic) facts for kids
A tautology is a statement or idea that is always true. It's like saying something that can't possibly be wrong, no matter what! The word "tautology" comes from an old Greek word meaning "saying the same thing."
Think of it this way: if you say, "It is either raining or it is not raining," that statement is always true. It has to be one or the other! That's a tautology.
The idea of tautologies in logic was first used by a smart thinker named Ludwig Wittgenstein in 1921.
What is a Tautology?
In logic, a tautology is a special kind of statement that is always true. It doesn't matter what specific details you put into the statement; it will still be correct.
For example, in math, if you say "2 + 2 = 4," that's always true. It's a basic fact that doesn't change.
Everyday Examples
You might hear or use tautologies in everyday talk without even realizing it! They often sound like someone is just repeating themselves.
Here are some examples:
- "I know this is Wikipedia because I know this is Wikipedia."
- "The first rule of the Tautology Club is the first rule of the Tautology Club."
- "It is what it is."
These sentences are true because they basically say "A is true because A is true." If the first part is true, then the whole statement is true. If the first part isn't true, then the whole statement still works out because it's just repeating itself.
Related pages
See also
In Spanish: Tautología para niños
