48 Aristotle’s Doctrine of the Mean
Aristotle’s Doctrine of the Mean
(Originally appeared in History of Philosophy Quarterly 4/3, July 1987.)
Aristotle’s doctrine of the mean is sometimes dismissed as an unhelpful and unfortunate mistake in what would otherwise be — or perhaps, in spite of this lapse, still is — a worthwhile enterprise. Bernard Williams, for example, clearly regards it thus:
Aristotle’s…views on [virtue] are bound up with one of the most celebrated and least useful parts of his system, the doctrine of the Mean, according to which every virtue of character lies between two correlative faults or vices…, which consist respectively of the excess and the deficiency of something of which the virtue represents the right amount. The theory oscillates between an unhelpful analytical model (which Aristotle himself does not consistently follow) and a substantively depressing doctrine in favor of moderation. The doctrine of the Mean is better forgotten.[1]
Williams’s remark strikes me as both unfair to Aristotle and, perhaps as a result, blind to certain ethical insights of which Aristotle is keenly aware. In this essay I shall offer a more charitable interpretation of the doctrine of the mean. In sections I-III I bring together various things Aristotle says in developing his view that virtue or excellence lies in the observance of a mean. In section IV I turn to the obvious fact that as I have interpreted it the doctrine of the mean does not provide detailed and unambiguous guidance to agents deliberating in particular situations. I suggest that it was not intended to provide such guidance, and argue that this does not mean that it is not a useful part of Aristotle’s ethical theory worth the attention of moral philosophers.
I
Aristotle develops the doctrine of the mean in the course of his discussion of aretê, excellence or virtue, in Book II of the Nicomachean Ethics (see also Eudemian Ethics, Book II, chapters 3 and 5).[2] There he writes that
all excellence makes what has it good, and also enables it to perform its function well. For instance, the excellence of an eye makes the eye good and enables it to function well as an eye; having good eyes means being able to see well. Likewise, the excellence of a horse makes it a good horse, and so good at galloping, carrying its rider, and facing the enemy. If this is true in all cases, then, the excellence of a human being will be that disposition which makes him a good human being and which enables him to perform his function well. (1106a16-25)
The function or characteristic activity of human beings, Aristotle has argued in Book I, is “a way of living… consisting in the exercise of the psyche’s capacities in accordance with reason, or at any rate not in opposition to reason”; a good person “exercises these capacities and performs these activities well.” Excellence, then, is that condition which best suits us to perform those activities which are distinctively human. Hence the best life for a h