Moral philosophy (or ethics) forms a diverse and eclectic field, about which few accurate generalizations can be made.* However, I think I detect a very widespread preference for concepts whose significance is always the same–either positive or negative–wherever they appear. In defining moral concepts, philosophers like to identify necessary and sufficient conditions, such that if something can be done, it will always be obligatory, praiseworthy, desirable, permissible, optional, regrettable, shameful, or forbidden to do it. These moral propositions may have to be considered along with other valid propositions that also apply in the same circumstances. For instance, honesty may be obligatory (or at least praiseworthy); yet tact is also desirable. Honesty and tact can conflict. Hardly anyone doubts that we face genuine moral conflicts and dilemmas. Yet the hope is to develop general moral propositions, built of clearly defined concepts, that are always valid, at least all else considered.
But what should we say about complex and ambiguous phenomena that have evolved over biological and historical time and that now shape our lives? I am thinking of concepts like love (recently discussed here), marriage, painting, the novel, lawyers, or voting. We can’t use these words in a deontic logic made up of propositions like “P is necessary.” They are sometimes good and sometimes not. We could try to divide them into subconcepts. For instance, love could be divided into agape, lust, and several other subspecies; painting can be categorized as representational, abstract, religious, etc. Once we have appropriate subconcepts, we can say that they have a particular moral status if (and only if) specified conditions apply.
The urge is to avoid weak modal verbs like “may” and “can” or other qualifiers like “sometimes” and “often.” Love can be wonderful; it can also be a moral snare. Paintings sometimes invoke the sublime; sometimes they don’t. Lawyers have legitimate and helpful roles in some cases and controversies, but not in others. A core philosophical instinct is to get rid of these qualifiers by using tighter definitions. For example, agape (properly defined) might turn out to be always good and never a snare. You always need and have a right to a lawyer when you are arraigned. All paintings by Giorgione or similar to Giorgione’s are sublime. And so on.
My fear is that the pressure to avoid soft generalizations prevents us from saying anything useful about a wide range of social institutions, norms, and psychological states. They don’t split up neatly into subcategories, because they didn’t evolve or develop so neatly. They won’t work in a deontic logic unless we allow ourselves soft modals like “may” and “can.” And yet, outside of philosophy, much of the humanities involves moral evaluations of just such concepts. For example, a great nineteenth-century novel about marriage does not claim that marriage is always good or bad, or always good or bad under specified conditions. The novel evaluates one or two particular marriages and supports qualified conclusions: marriage (in general) can be a happy estate, but it also has dangers. It is wise, when contemplating a marriage, to consider how events may play out for both partners. “Marriage,” of course, means marriage of a specific, culturally-defined type (monogamous, exogamous, heterosexual, voluntary, permanent, patriarchal, and so on). That institution will evolve subtly and may be altered suddenly by changes in laws and norms. The degree to which the implied advice of the novel generalizes is a subtle question which the novel itself may not address.
Much contemporary philosophy has a forensic feel. The goal is to work out definitions and rules that, like good laws, permit the permissible and forbid the evil. I do not doubt the value of forensic thinking–in law. I do doubt that it is adequate for moral thinking. It seems to me that the search for clearly defined and consistent concepts narrows philosophers’ attention to discrete controversial actions (abortion, torture, killing one to save another) and discourages their consideration of complex social institutions. It also directs their energy to metaethics, where one can consider questions about moral propositions, rather than “applied” topics, which seem too messy and contingent.