In New English Review Dalrymple recounts a dream that caused him to wonder: Is honor a virtue? That depends, he says. How can we know when it becomes a vice? That also depends.

The fact that there is no precise point or moment at which virtue turns into vice suggests that there will never be any categorical imperatives, at least not of any use to the person who is trying to behave well…The ethical life is a course steered eternally between Scylla and Charybdis, between the rock and the whirlpool of different manifestations of intransigence.

That there is no rule for discerning when virtue turns to vice does not mean that there is no real distinction between them, any more than the fact that there is no precise point at which a man becomes tall means there is no distinction between a tall man and a short one.