We have two twin brothers, Bill and Ted. Each of them has an identical chariot. Now, let's just say for shits and giggles, that these brothers one day become bored, and opt to trade one plank from their chariots-so now, each chariot contains one plank from the other. Unfortunately for us, these two brothers are particularly masochistic towards students of philosophy, and so continue to trade planks, one a day, until all of the planks have been traded. Uh-huh. So, does each brother still have his own chariot, or does Bill now have Ted's chariot, and vice versa?

After two Advil, a cigarette, and a shot of Goldschlager, I came to a conclusion. Each brother still possessed his own chariot. My logic here stems from my original argument from the Ship of Theseus question: as each plank is added, it is incorporated into the original, and so becomes a part of the original. Since the brothers are just trading planks, this theory of mine still works.

As there is always more than one answer to a philosophy question, I'm sure that some of you are thinking, "that's just a bunch of camel dung. The two brothers have swapped chariots-they may have done it the hard way, but they still traded." Ok then, answer me this: when did the brothers cease to posses their own chariot? After 1 plank? After a quarter had been swapped, or half? Did the last plank have to be traded for them to have their brother's chariot? Ok, now that you have decided that, my next question shouldn't be too astonishing: Why?