15 paradoxes that will make your head explode

"I know one thing," Socrates famously said. "That I know nothing."

It's a crucial insight from one of the founders of Western philosophy: You should question everything you think you know.

Indeed, the closer you look, the more you'll start to recognize paradoxes all around you.

Read on to see our favorite Catch-22s from Wikipedia's epic list of more than 200 types of paradoxes.

Gus Lubin contributed to an earlier version of this article.