  There is a very different way of understanding a moral principle, as ‘contributory’ rather than as absolute. Understood in this second way, our principle maintains that if an action involves breaking a promise, that counts against it. The action is the worse for being a promise-breaking. Of course it may be the worse for being a promise-breaking but the better for some other feature that it has—that of being kindly meant, say. The contributory conception of moral principles allows that more than one principle can apply to the case before us, since it holds that each principle is, as it were, partial; each specifies how things are only in a certain respect. But actions have many relevant features, some counting in favour and others against. Whether the action is overall right or wrong can only be determined by the overall balance of right and wrong in it. The contributory principles do not themselves tell us how to determine that balance. They only specify contributions one by one, and leave us to work out how these add up. Some people suppose that the principles can themselves be ranked in order of importance; if that were right, it would be of some help to us in working out what matters most in a given case. Others suppose that there is no available lexical ordering of such a sort, and that the matter is left to unaided ‘judgement’.