A branch of human learning that is at first strong and healthy may early contract some malady that distorts its further growth. So it was, I have elsewhere argued, with Aristotle’s logic: he began by distinguishing two sharply distinct categories, names (onomata) and predicables (rhēmata)but came to merge these categories in the category of terms (horoi) which could pass freely between subject—role and predicate—role. So it happened also, I shall now argue, with deontic logic: the discipline early lost one of the features given it by its founding father, Georg Henrik von Wright, and he too acquiesced in a change that may then have appeared small but has turned out to be fundamental and fateful.