Deontic Logic

Deontic logic is the most important of all the philosophical fields. As far as Aristotle, philosophers have studied deontic logic, but the modern deontic logic began with GH.Wright's An Essay on Deontic Logic in Mind. From then, based on its paradoxes, philosophers have been extending and deepening its research, and remolding its system. Deontic Logic have gone through the process from classical to monistic, from monistic to dualistic, from proposition to predicate, from unconditional to conditional, from pure form to natural language, from deontology to action. And it is still and will be on the dynamic process.This paper analysises and discusses the deontic paradoxes based on the brief introduction of the monistic deontic logic and dualistic deontic logic, and puts forward the author's own initiatory thinking.This paper consists of the following three chapters:Chapterl Analysising deontic propositions. Chiefly analysising deontic operators "duty" "permission" "forbidden" and analysising the relation between them.Chapter2 Introducing the ten systems of monistic deontic logic. Chiefly introducing the weakest :OK, and adding the two operators:"advocacy", "limitation", and a new axiom Op→Pp, building a new system OAP, and giving the proof of some theorems, analysing its syntax and semantic, and judging its semantic consistency and completeness.Chapter3 Analysising and discussing the deontic paradoxes and former solving methods, putting forward the author's own initiatory thinking.