Natural Law and the epistemology of permissions

It is hard to know that something is permissible, because an action is permissible provided that no moral consideration is decisive against it. Thus, it seems, to know that an action is permissible requires surveying the infinite set of all possible moral considerations and checking that none of them rules out the action.

But natural law ethics provides a handy shortcut:

1. Actions characteristic of a kind of being are permissible in relevantly normal circumstances.

Principle (1), for instance, makes it difficult to defend strong versions of antinatalism or of ethical vegetarianism by conferring a default permission status on reproduction and the eating of meat, since we are organisms (and hence characteristically reproduce in appropriate circumstances) and omnivores (and hence have a characteristic diet that includes meat).

The natural permission principle shifts the discussion from the question whether a given action type, characteristic of us humans, is generally permissible, to the question whether the circumstances at hand are relevantly normal. Thus, (1) still leaves open the possibility of an antinatalism that holds that things are so abnormally bad that it’s wrong to reproduce, or an ethical vegetarianism on which global conditions require us to forego meat.

Subscribing to principle (1) also explains the incredulous stare I see on students’ faces when I explain Andrea Dworkin’s view that heterosexual intercourse is always wrong.