John Ruskin, from Unto This Last:
No human actions ever were intended by the Maker of men to be guided by balances of expediency, but by balances of justice. He has therefore rendered all endeavours to determine expediency futile for evermore. No man ever knew, or can know, what will be the ultimate result to himself, or to others, of any given line of conduct. But every man may know, and most of us do know, what is a just and unjust act.