What ought we to do? More carefully put: how are we to judge what we ought to do? What are the principles? The question has a history as long as that of the human race, and most people believe, or pretend, that it’s still a real head-scratcher. But the answer is well-known, even if seldom acknowledged.

In the philosophical tradition it is called utilitarianism, but this is an awfully frumpy name for such a beautiful idea.

Judge your actions by whether you’re being kind to other people. That’s it. That’s how you tell. You should be regular, plain old, garden-variety good to people – in other words, benevolent, compassionate, friendly, gentle, helpful, loving, neighborly, peaceable, sweet, sympathetic, tender, understanding, warm. If you want to know how to behave, that’s how. It really is that simple. Ethics is no more and no less than the study of how to make acts of kindness more likely, and acts of violence, less.

The persistent philosopher might insist, “Yes, but why do we prefer tenderness to harm?” Resisting the impulse to slap this addle-pated misanthrope upside the head, we can point to an even more fundamental principle. We want people to be happy. (And yes, I mean all of them.) Therefore the task of ethics is to consider how to get them to treat each other well, because in general it is other people who have the greatest effect on each person’s happiness.

Happiness or the lack thereof is as near an absolute and eternal principle as human beings will ever find. As Janet Radcliffe Richards puts it:

I take it as morally fundamental that suffering is intrinsically bad. Some people deny this; and if they persist in this denial after clarification (they usually turn out to mean that suffering can sometimes be instrumentally good – which is a quite different matter) there may be nothing more that argument can do. And if people really don’t think it is morally important to avoid or prevent suffering, I’m not sure what you can do with them except put them on a desert island with no people or animals, so that they can’t do any harm. [Quoted in Julian Baggini and Jeremy Stangroom (2003), What philosophers think, p.27.]

Will what you are about to do make who you’re about to do it to more happy, or less? That is the whole thing. The history of ethical philosophy is the history of attempts to evade this simple criterion – to invoke exceptions, exemptions, and loopholes. But there is no reasonable excuse for making others unhappy. We can’t prevent people from being mean, but we can refuse to be fooled when they claim that actually, they’re being nice, if we would just understand them properly. In most such cases we can reply confidently, “No, what you just did was not kind. After all, it’s not actually that hard to tell the difference.”