Philosophy
Relevance Logic and the Critique of Classical Entailment
Quick fact
In classical logic, the argument 'The moon is made of cheese; therefore, 2+2=5' is perfectly valid, because material implication treats any implication with a false antecedent as true.
Why this is interesting
Have you ever heard that a false statement implies anything? In classical logic, that's true—but it seems to make nonsense of reasoning. How can logic allow such irrelevant conclusions?