Title: Is Deontic Logic Too Much for Legal Reasoning?

Speaker: Tianwen Xu (Nanjing University)

Time: Mar. 17th (Tuesday), 15:10 - 18:00

Location: Room 314, Teaching Building No.2 (北京大学第二教学楼314)

Abstract:

Whether deontic logic can be useful for legal reasoning has long been debated. Contrary to their seemingly natural affinity, many have argued that deontic logic is too much for legal reasoning, that it is too deep, unnecessarily complex or irrelevant for the subject matter of law. This talk offers a comprehensive inspection of the issue. I start with a recap of the history of applying deontic logic to law, from early attempts in the 1960s to more recent advances. Then I assess the actual impacts of these efforts, which have been by and large limited, from both a philosophical and a computational perspective. The reason that deontic logic is still struggling with reasoning of law, as I continue to argue, is not that deontic logic is too much, but that there are so many peculiarities of law that pose fundamental challenges for deontic logic. These include the unique practice of normative reasoning in the domain of law, the vivid modalities entangled in legal norms, the tension between some common features of legal reasoning and the conventional assumptions in deontic systems, etc. We are not in a position to judge the usefulness of deontic logic, unless we have taken these challenges seriously.