Full Idea
What makes an act involuntary is not ignorance in the choice (which is a cause of wickedness), nor ignorance of the universal principle (which is blameable), but particular ignorance, of circumstances and objects.
Gist of Idea
Acts may be forgivable if particular facts (rather than principles) are unknown
Source
Aristotle (Nicomachean Ethics [c.334 BCE], 1110b31)
Book Reference
Aristotle: 'Ethics (Nicomachean)', ed/tr. ThomsonJ A K/TredennickH [Penguin 1976], p.113
A Reaction
The point here has to be that particular facts are much more significant in moral decisions than principles. This is the whole key to virtue theory - that principles are overruled by the facts of a situation, and only virtue can see you through.