I’ve been doing some remedial reading of Aristotle these days. The following comes from Nicomachean Ethics I.7:
[A clearer account of happiness] might perhaps be given, if we could first ascertain the function of man. For just as for a flute-player, a sculptor, or an artist, and, in general, for all things that have a function or activity, the good and the ‘well’ is thought to reside in the function, so would it seem to be for man, if he has a function. Have the carpenter, then, and the tanner certain functions or activities, and has man none? Is he born without a function? Or as eye, hand, foot, and in general each of the parts evidently has a function, may one lay it down that man similarly has a function apart from all these? What then can this be? Life seems to be common even to plants, but we are seeking what is peculiar to man. Let us exclude, therefore, the life of nutrition and growth. Next there would be a life of perception, but it also seems to be common even to the horse, the ox, and every animal. There remains, then, . . . an activity or actions of the soul.
Two things strike me as odd about this line of reasoning. The first is Aristotle’s assumption that “the” function of man — the function most relevant to his happiness — must be something peculiar to his species, and that we can begin by setting aside all functions which man has in common with other organisms. The implication is that in a differently populated universe, one in which man was still man but shared his world with a different cast of organisms, Aristotle’s reasoning might have led to vastly different conclusions. For example, in a universe with many highly intelligent species (and our universe may yet turn out to be such a place) the soul and its virtues would no longer be peculiar to man and could no longer be considered central to man’s happiness.
The focus on a distinctive or peculiar function also raises the question, “Peculiar to whom or what group?” Aristotle focuses on what distinguishes the human species from others, but that focus seems arbitrary. He could just as easily have focused on what distinguishes Greeks from barbarians, or aristocrats from commoners, or each individual from his fellows. Or, going the other direction, he could have thought of himself more broadly as a hominoid and found that happiness comes from exercising our distinctive ability to brachiate. Aristotle rejects both the too-narrow focus (I’m a tanner, so my function is to make leather) and the too-broad (I’m an organism, so my function is to vegetate), zeroing in on the species level, but he never explains why or makes it clear why being a good man is more important than being, say, a good carpenter or a good mammal.
The second thing I noticed is how facilely Aristotle makes the jump from functional organs to functional organisms, passing over one of the most significant (and, before Darwin, baffling) features of biology — namely, that while individual organs tend to be very clearly “for” something, whole organisms have no obvious function at all other than the circular ones of staying alive and reproducing their kind. (More precisely, every organism’s function is to keep its genes alive, whether in original form or as copies, and it’s the genes that have no function other than to go on existing. But Aristotle obviously couldn’t have known that.) Aristotle, being both knowledgeable about biology and skilled in reasoning about purposes, would have been the perfect person to notice this and call it to everyone’s attention, but instead he contents himself with the rather weak move of choosing an organism’s most distinctive organ (the mind, in the case of man) and ascribing that organ’s function to the organism as a whole.