There is something about practical things that knocks us off our philosophical high horses. Perhaps Heraclitus really thought he couldn’t step in the same river twice. Perhaps he even received tenure for that contribution to philosophy. But suppose some other ancient had claimed to have as much right as Heraclitus did to an ox Heraclitus had bought, on the grounds that since the animal had changed, it wasn’t the same one he had bought and so was up for grabs. Heraclitus would have quickly come up with some ersatz, watered-down version of identity of practical value for dealing with property rights, oxen, lyres, vineyards, and the like. And then he might have wondered if that watered-down vulgar sense of identity might be a considerably more valuable concept than a pure and philosophical sort of identity that nothing has.
John Perry, introduction to Identity, Personal Identity, and the Self
He bought the present ox along with the future ox. He could have just bought the present ox, or at least a shorter interval of one. This is known as “renting”.
He bought the ones on the future side of that worldline.
It’s convenient that way, and humans are good at keeping track. He could have bought any combination of future oxen the guy owns. This has the advantage of later oxen being in the same area as earlier oxen, simplifying transportation.
I’m not making myself clear. It’s clear from what you say that if Heraclites bought an ox yesterday, he owns an ox today. But in order to say that he owns this particular ox, he needs a better system of identity than “you never step into the same river twice”.
It’s a sensible system for deciding how to buy and sell oxen because it minimizes shipping costs. It’s a less sensible way to, for example, judge the value of a person. Should I choose Alice of Bob just because Bob is at the beginning of a world-line and Alice is not?
This does kind of come back to arguing definitions. The common idea of identity is really useful. If a philosopher thinks otherwise, he’s overthinking it. “Identity” refers to something. I just don’t think it’s anything beyond that. You in principle could base your ethics on it, but I see no reason to. It’s not as if it’s something anybody can experience. If you base your anthropics on it, you’ll only end up confusing yourself.
John Perry, introduction to Identity, Personal Identity, and the Self
He bought the present ox along with the future ox. He could have just bought the present ox, or at least a shorter interval of one. This is known as “renting”.
Which future ox did he buy?
Sorry. The future oxen.
Of the many oxen at a given point in time in the future, which one did he buy?
Oh. I see what you mean.
He bought the ones on the future side of that worldline.
It’s convenient that way, and humans are good at keeping track. He could have bought any combination of future oxen the guy owns. This has the advantage of later oxen being in the same area as earlier oxen, simplifying transportation.
I’m not making myself clear. It’s clear from what you say that if Heraclites bought an ox yesterday, he owns an ox today. But in order to say that he owns this particular ox, he needs a better system of identity than “you never step into the same river twice”.
It’s a sensible system for deciding how to buy and sell oxen because it minimizes shipping costs. It’s a less sensible way to, for example, judge the value of a person. Should I choose Alice of Bob just because Bob is at the beginning of a world-line and Alice is not?
This does kind of come back to arguing definitions. The common idea of identity is really useful. If a philosopher thinks otherwise, he’s overthinking it. “Identity” refers to something. I just don’t think it’s anything beyond that. You in principle could base your ethics on it, but I see no reason to. It’s not as if it’s something anybody can experience. If you base your anthropics on it, you’ll only end up confusing yourself.
Alternatively, he purchased the present ox using the ox-an-hour-ago as payment.
No. There is nobody to make that transaction with, and his past self still used the past ox, so he can’t sell it.
What those eggheads need is a good ass-kicking!
A praiseworthy sentiment.