Friday, June 28, 2013
Does Life Have a Purpose?
One of my favorite dinosaurs is the Stegosaurus, a monster from the late Jurassic (150 million years ago), noteworthy because of the diamond-like plates all the way down its back. Since this animal was discovered in the late 1870s in Wyoming, huge amounts of ink have been spilt trying to puzzle out the reason for the plates...But this essay is not concerned with dinosaurs themselves, rather with the kind of thinking biologists use when they wonder how dinosaur bodies worked. They are asking what was the purpose of the plates? What end did the plates serve? Were they for fighting? Were they for attracting mates? Were they for heat control? This kind of language is ‘teleological’ — from telos, the Greek for ‘end’. It is language about the purpose or goal of things, what Aristotle called their ‘final causes’, and it is something that the physical sciences have decisively rejected. There’s no sense for most scientists that a star is for anything, or that a molecule serves an end. But when we come to talk about living things, it seems very hard to shake off the idea that they have purposes and goals, which are served by the ways they have evolved. more