My Dante book (in progress) is really an essay

on the limitations of moral theory. But what is that? I’m playing

with the following definition: Moral theories are collections of descriptive

terms, each of which has a known moral valence. For example, "unjust"

is a descriptive term with moral significance. We might argue that anything

that is "unjust" is wrong—at least all else being equal.

In that case, the moral valence of the term "unjust" is negative;

calling something "unjust" pushes us toward rejecting that action

(or institution, or character).

Knowing the moral valence of a descriptive term does not always tell

us what to do, because a single act can be described in multiple ways.

A given action may be "unjust" but also "loving."

(For example, a parent might favor her own children over others.) In such

cases, the negative moral valence of injustice is countered by the positive

moral valence of love, and we have a difficult decision to make. In another

kind of situation, an action may be "unjust" but also "necessary";

and if something is necessary, then we may have to ignore moral considerations

altogether.

Few (if any) philosophers have ever believed that moral theories could

be sufficient to determine action; we also need judgment to tell us which

moral terms to apply in particular cases, and how to balance conflicting

terms. Nevertheless, philosophers generally think it is useful to have

a moral theory composed of terms with known moral valences.

A moral theory can simply be a list of such terms (this was W.D. Ross’

view); but preferably it is an organized structure. For example, a theorist

may argue that some moral terms underlie and explain others, or trump

others, or negate others. The more the full list can be organized and/or

shortened, the more the theory has achieved.