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.

This essay deals with the concept of negation in Deontics. In relation with this concept, the polish logician Jerzy Sztykgold seems to put forward these two thesis: a) a norm may have a negation; b) a norm may be a negation. Sztykgold studies the concept of Inegation of a norm through the analysis of other two concepts of a right or of a duty and the concept of opposition of behaviour), and, as early as 1936, he puts hirnself in a (...) clear position in relation to the problem of the possibility of a logic of norms: There is a deontic analogonof truth, which is the słuszność consequently, for the norms, entities of which the słuszność is predicated, are valid the thesis of the propositional logic that are valid for the apophantic sentences. (shrink)