How should one live? There are few questions, I think, that are as gripping and as inescapable as this one. Unlike many of the other classical questions of philosophy, this question — the central question of moral philosophy — seems pressing and important. It matters what answers we come up with, for it matters what I do with my life. What I make of myself, how I live, what I do, what kind of person I become — these things are of vital concern to each of us, even if few of us normally reflect on them in a systematic or critical fashion.

Moral philosophy attempts to answer the question of how one should live. Because of the staggering difficulty and significance of the question, any attempt to provide an answer can seem arrogant, pretentious, or embarrassing. Who could be so foolish, so naive, or so dogmatic, as to think that they had themselves (finally!) arrived at the truth about how to live? Indeed, many of us have learned to pretend — or have even fooled ourselves into thinking that we believe — that there are no correct answers here, that ethics is all simply a matter of opinion.

And yet, on reflection, most of us do in fact think that there are right and wrong answers in ethics. Here is a simple example: it would be immoral to set a child on fire for the mere pleasure of watching him burn. Is there anyone who seriously doubts the truth of this claim?