This article contains an overview of the author's long-standing involvement with deontic logic, both from a technical and from a wider philosophical point of view. As far as the formal aspects of deontic logic are concerned, the author describes his intellectual development from the original discovery of the analogy between modal (and deontic) notions on the one hand, and quantifiers on the other, through the formulation of a systematic theory of dyadic deontic concepts, to the proposal of a formal logic of action as a foundation for deontic logic. In a more philosophical vein, the author discusses such questions as the very possibility of deontic logic if norms have no truth-value, the relation between the descriptive interpretation of classical deontic logic and the logic of norm-propositions, the correct representation of conditional or hypothetical norms, the distinction between moral obligation and practical necessity, and the interdefinability of permission and obligation.