Utilitarianism is a great idea with an awful name. It is, in my opinion, the most underrated and misunderstood idea in all of moral and political philosophy.

I recall my eventual dissertation supervisor, Bernard Williams, saying to me once that he didn’t think that anyone could do ethics competently without a thorough grounding in logic. I nodded solemnly as if to register agreement, though I had never spent a minute studying logic and didn’t even know what a modus ponens was—in fact, I still don’t, though I know it has something to do with p and q.

If the reader wishes to form an impartial judgment as to what the fundamental problems of Ethics really are, and what is the true answer to them, it is of the first importance that he should not confine himself to reading works of any one single type, but should realize what extremely different sorts of things have seemed to different writers, of acknowledged reputation, to be the most important things to be said about the subject.

In ethics, as in mathematics, the appeal to intuition is an epistemology of desperation.

[T]he plain duty of each and all of us is to try to make the little corner [of the world] he can influence somewhat less miserable and somewhat less ignorant than it was before he entered it.

Attempts to ground social policy and moral judgment on a biological foundation have had a long but not always philosophically distinguished history.

[M]orality is founded in a sense of the contingency of the world, and it is powered by the ability to envisage alternatives. Imagination is central to its operations. The morally complacent person is the person who cannot conceive how things could have been different; he or she fails to appreciate the role of luck—itself a concept that relies on imagining alternatives. There is no point in seeking change if this is the way thingshave to be. Morality is thus based on modality: that is, on a mastery of the concepts of necessity and possibility. To be able to think morally is to be able to think modally. Specifically, it depends upon seeingother possibilities—not taking the actual as the necessary.

What principles should govern human action? As rational beings, we should act rationally. As moral beings, we should act morally. What, in each case, are the principles involved? What is it to act rationally, or morally? It is often thought, or said, that philosophers are preeminently the people who have (and have neglected) amoral obligation to apply theirrational skills to these great questions.

In the mid-1980s I attended a series of graduate seminars, run by Derek Parfit, on Sidgwick’sMethods of Ethics. Parfit began the first seminar by claiming that theMethods was the greatest book on ethics ever written.

Many religious persons think that the highest reason for doing anything is that it is God’s Will: while to others ‘Self-realisation’ or ‘Self-development’, and to others, again, ‘Life according to nature’ appear the really ultimate ends. And it is not hard to understand why conceptions such as these are regarded as supplying deeper and more completely satisfying answers to the fundamental question of Ethics, than those before named: since they do not merely represent ‘what ought to be’, as such; they represent it in an apparently simple relation to what actually is. God, Nature, Self, are the fundamental facts of existence; the knowledge of what will accomplish God’s Will, what is, ‘according to Nature’, what will realise the true Self in each of us, would seem to solve the deepest problems of Metaphysics as well as of Ethics. But […] [t]he introduction of these notions into Ethics is liable to bring with it a fundamental confusion between “what is” and “what ought to be”, destructive of all clearness in ethical reasoning: and if this confusion is avoided, the strictly ethical import of such notions, when made explicit, appears always to lead us to one or other of the methods previously distinguished.

I persist in thinking that the puzzle of ethics is starting to come together, and that few, if any, pieces are missing.

And now I must say that if I contemplate what Ethics really would have to be if there were such a science, this result seems to me quite obvious. It seems to me obvious that nothing we could ever think or say should be /the /thing. That we cannot write a scientific book, the subject matter of which could be intrinsically sublime and above all other subject matters. I can only describe my feeling by the metaphor, that, if a man could write a book on Ethics which really was a book on Ethics, this book would, with an explosion, destroy all the other books in the world.