Dialetheism is the idea that some things can be both true and false at the same time. That might sound strange, because most of the time we think something has to be either true or false — not both.
For example, if I say “It’s raining,” we think it can’t also be true that “It’s not raining” at the same time in the same place. But dialetheism says there are rare cases, called true contradictions, where both the statement and its opposite are true together.
One famous example is the Liar Paradox, where someone says “This sentence is false.” If that’s true, then it must be false — but if it’s false, then it must be true! Instead of saying this is just nonsense, dialetheists believe it’s a real contradiction that’s both true and false.
To deal with this, they use something called paraconsistent logic, which is a special way of thinking that can handle contradictions without everything going crazy.
So, dialetheism challenges the usual rule in logic — the Law of Non-Contradiction — and asks us to think in new ways about truth, falsehood, and what makes a statement meaningful.