Abstract
Here is a puzzle from the Stoic, Chrysippus: There was once a man called Dion, who was unfortunate enough to have his foot annihilated. Thereafter, he was known as Theon. Theon is identical to what was left over after Dion’s foot was removed. That is, Theon is that part of Dion that does not include his foot. If all this is true, then Theon is a proper part of Dion. That is, he is a part of Dion, but not identical to Dion. But if that’s right, then, surprisingly, Dion didn’t survive the loss of his foot.