CONCEPT
Thick Ethical Concepts
Williams's distinction between thick concepts (courageous, cruel, gracious) that fuse description and evaluation and thin concepts (good, right, wrong) that abstract from particularity — and the argument that moral life is impoverished when conducted in thin vocabulary alone.
Thick ethical concepts carry evaluative and descriptive content simultaneously. To call an action courageous is not merely to approve of it but to characterize it as involving a specific quality — the relationship between fear and resolve — that looks different from other forms of goodness. Thin concepts (good, bad, right, wrong) carry evaluative content but almost no descriptive content; they issue verdicts without characterizing. Williams argued that thick concepts are the primary vocabulary of actual moral life, that they emerge from specific communities of practice, and that the morality system's preference for thin universal categories produces systematic blindness to the textured distinctions thick concepts preserve. The AI discourse, conducted almost entirely in thin categorical vocabulary, exemplifies the impoverishment.
In The You On AI Field Guide
Williams developed the distinction in Ethics and the Limits of Philosophy (1985), though the idea draws on earlier work by Philippa Foot and Iris Murdoch. The argument