I learned about the philosopher Zeno of Elea from Douglas Hofstadter's Gödel, Escher, Bach. He was famous for coming up with several paradoxes. Here's a neat one:

"In a race in which the tortoise has a head start, the swifter-running Achilles can never overtake the tortoise. Before he comes up to the point at which the tortoise started, the tortoise will have got a little way, and so on ad infinitum. -- Internet Encyclopedia of Philosophy"

He had a related paradox which stated that motion was inherently impossible. I like using this one when my wife wants me to empty the trash or something else which requires movement.