Monadic Deontic Logic And Some Paradoxes In It

Deontic logic was created as a class of symbolic logic that study deontic notions as obligation, permission, impermission, etc. in the1950’s. It’s a branch of generalized modal logic, and also is referred to as normative logic or obligatory logic. Since founded by von Wright in1951, modern deontic logic experienced the rapid development from Syntax to Semantics, from absolute deontic logic to relative deontic logic, and from propositional deontic logic to predicate deontic logic, during which many well-known logicians have made unremitting efforts. Deontic logic has been strongly influenced by ideas in early alethic modal logic. Not only it has theoretical importance as modal logic, but also its practical significance is more prominent. According to the diversity research content, deontic logic can be divided into absolute deontic logic and relative deontic logic, where absolute deontic logic can be divided into unadorned absolute deontic logic and alethic absolute deontic logic. The essay will discuss absolute deontic logic and give some views on these main problems in monadic systems of deontic logic. by expounding development history and background knowledge of deontic logic, and by analyzing most typical monadic systems of deontic logic in unadorned absolute deontic logic and alethic absolute deontic logic respectively. The main content of the essay be divided into three sections:The first section:Summary of deontic logic. In this section, preliminary knowledge of deontic logic is expounded in four aspects:1) development history of deontic logic.2) alethic modal logic.3) analogous-modal traditional scheme, and4) propositional language and some presupposed principle of deontic logic.The second section:typical monadic systems of deontic logic. The section analyze Standard Deontic Logic (SDL) that’s the most typical system of unadorned absolute deontic logic, and The Andersonian-Kangerian reduction that’s the most typical system of alethic absolute deontic logic from syntax the and semantics respectively, also some additional systems of these.The third section:some problem and reflection of these. In this section, according to the different practicable principle in SDL. these main paradoxes in deontic logic are classified and expounded, and will be analyzed so that try to find solution. All paradoxes can be divided into:problems centering around deontic logic; problems centering around NEC; problems centering around RM; problems centering around NC. OD;problems on deontic conditionals; problems on expressive inadequacies of SDL problems Surrounding agency in deontic Contexts; challenges regarding time, change and obligation.