Eomer said, 'How is a man to judge what to do in such times?' 'As he has ever judged,' said Aragorn. 'Good and evil have not changed since yesteryear, nor are they one thing among Elves and another among Men. It is a man's part to discern them, as much in the Golden Wood as in his own house.'"
--J.R.R. Tolkien in The Two Towers