The donkey that starved because it couldn't pick a side

Imagine a hungry donkey placed exactly midway between two identical piles of hay, with no reason to prefer one over the other. If choice must be driven by a reason, the donkey can never move, and starves between two equally good meals. The puzzle is named for medieval philosopher Jean Buridan, though it never appears in his own writing and traces back further to Aristotle's example of a man caught between equal hunger and thirst.

— Aristotle, On the Heavens (De Caelo) — Book II, Chapter 13, c. 350 BC