When people in modern Western cultures think about morality, they first think about what is morally permissible or impermissible, right or wrong. But there are other matters of moral concern. Of special importance among these are questions about what things are good or bad and, more specifically, about what things are good or bad for people.

Exactly what is good for a particular agent, Murphy, will depend on Murphy's character, ability, and circumstances, and what is good for Murphy may be very different from what is good for Marlow. But most of the differences between what is good for Murphy and Marlow concern instrumental goods – things that are good because they are means to something else. If one focuses on intrinsic goods – things that are good in themselves – without regard to their consequences, then there may be much less variation from individual to individual. Size-7 shoes are good for Murphy while size-12 shoes are good for Marlow, but both pairs serve the same end. In strumental goods, like shoes of the right size, are good only if the ends they serve are good. So if nothing were good in itself, then nothing could be good as a means to some other end. There must be intrinsic goods in order for there to be instrumental goods. A central problem of moral philosophy has been to determine what things are intrinsically good for human beings. Thus Aristotle, for example, held that happiness was the sole intrinsic good.