I'm not sure I understand what you think the gap in his argument is (which is not to say it's not gappy). In I.7 he says specifically that human beings have a variety of aims and activities, but that a life in accordance with reason is the chief aim because it's the activity we pick out when we say someone is a good human being (as opposed to a good carpenter). So adresses, if inconclusively, the question 'Why is this our chief aim?' by pointing out that when we call a carpenter good, we mean that he's good at the activity of carpentry...in other words, the thing we picked out when we called him a 'carpenter'. In ethics, we're concerned with being a good human, so what activity do we pick out when we call someone simply a 'human'?
Is this argument circular? Or at least a disguised appeal to intuition?
"When we think of what a good human is, we think of a rational human. Therefore, what sets humans off is being rational. Therefore, the final cause of humans to be rational. Therefore, a good human is a rational human."
Couldn't you skip straight to "If we think X is good, then X is good"?
Sorry, my summery left some important points in the dark. Aristotle is saying something like this:
When we say something is good, we say that it is a good X or Y, not good simpliciter. When we say someone is a good flute player, we don't mean that they are good and a flute player, but that they are good qua flute player. By picking someone out as a good flute player, we are already deploying some idea of what it is that distinctively they do and what it is that they aim to do qua flute player.
Now, we're presently asking ourselves what the good life is, and ...
Today's post, Three Fallacies of Teleology was originally published on 25 August 2008. A summary (taken from the LW wiki):
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