Deon in Deontics

Abstract.The starting point of deontic logic is the distinction between non‐normative necessity and normative necessity. The first part of the paper shows that the distinction between normative necessity and non‐normative necessity occurs already in Aristotle's Orgunon. The second part of the paper makes a further distinction within normative deon itself: The distinction between deontic deon and anankastic deon. Anankastic deon behaves differently from deontic deon in a very important respect: Deontic indifference has no anankastic counterpart.