Alpha approaches Beta, asking for payment of a debt.

Beta: If you had an odd number of pebbles — or for that matter an even one — and then chose to add or subtract a pebble, do you think you would have the same number?

Alpha: No.

Beta: If you had a measure of one cubit and chose to add or cut off some length of it, that measure would no longer exist, would it?

Alpha: No.

Beta: Well now, think of a human in the same way: one human is growing and another is diminishing. All are constantly in the process of change. But what by its nature changes and never stays put must already be different from what it changed from. You and I are different from who we were yesterday, and by the same argument will be different again tomorrow.

Exasperated, Alpha strikes Beta.

Beta: Why are you angry with me?

Alpha: As someone nearby just demonstrated, it was not I who hit you, not I at all, but someone else altogether.

(From a fragment by Epicharmus.)