Monday, January 28, 2013

Breaking point

Here’s a bit of Aristotle De Caelo 2.13:
ὥσπερ ὁ περὶ τῆς τριχὸς λόγος τῆς ἰσχυρῶς μὲν ὁμοίως δὲ πάντῃ τεινομένης, ὅτι οὐ διαρραγήσεται, καὶ τοῦ πεινῶντος καὶ διψῶντος σφόδρα μέν, ὁμοίως δέ, καὶ τῶν ἐδωδίμων καὶ ποτῶν ἴσον ἀπέχοντος· καὶ γὰρ τοῦτον ἠρεμεῖν ἀναγκαῖον. 
This is like the hair that is stretched strongly but equally at every point at will not break, or like the case of the person who is intensely but equally thirsty and hungry, but who is equally distant from the food as from the drink – for he will necessarily stay put. 
Aristotle is interested in various explanations for why the earth stays where it is. He is discussing the idea that it stays where it is because of homoiotēs, i.e. because it is no closer to this edge of the cosmos that to the opposite edge and so has no more reason to move this way than that… Here are two other arguments of the same type.

I asked an engineer friend about the example of the hair. He said, first of all, that it is a silly example because as things are there will always be variations along the length of a hair or wire which mean that it will be weaker in one place than in another. This seemed to me to be a very unhelpful reaction since I wasn’t really interested in the facts of the matter. Just suppose that there were no such variations: this is a perfect and perfectly homogeneous hair or wire. Then what? He sighed and tried to leave. But I made him answer what he obviously thought was a very silly question. The answer I eventually got was that at a certain point the hair or wire would break at each and every place where there was a break between the atoms or molecules. This wouldn’t be of much interest to Aristotle, of course, who was convinced that atomism is a daft idea.

Then I wondered about the example of the person who is equally—and intensely—hungry and thirsty. There are obviously other versions of this (e.g. Buridan’s ass) but I like the detail in this version, particularly the idea that the opposing desires are for different objects but that the different objects are (i) desired with equal intensity and (ii) equally easy or equally difficult to obtain. There is no more reason to slake my thirst before satisfying my hunger than there is to satisfy my hunger before slaking my first. So, the argument goes, if I have no reason either to slake my thirst first or satisfy my hunger first I do neither – until, at least, one desire gets larger than the other or someone helpfully takes away the tray of biscuits and I then get released from my torture and pick up the mug of tea.

Here’s a thought: suppose this kind of reasoning is correct. Does it offer a way of avoiding acting in a way you know is contrary to your best interests? Suppose you know you’re the kind of person who over-indulges in puddings. One way to help yourself to do the right thing is to cultivate an equally intense desire for something else and make sure you have an equally easy-to-hand supply of all the different things you desire. This sounds like it might be more fun than Plato’s answer that you have to make sure you train your desires properly, have the desire for what is genuinely good always in command etc. etc. Instead, you should combat the potentially damaging desire by cultivating lots of other competing and equally intense desires. The just make sure that all of these competing desires are equally easy to satisfy.  You run the risk of never doing anything at all, but at least you won’t act in accordance with a damaging desire.

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