Dear Everyone,

I am happy to announce a talk by Professor Van Der Torre from University of Luxembourg as follows. Everyone is welcome.

Speaker: Professor Van der Torre https://scholar.google.com/citations?user=kRoU8dEAAAAJ&hl=ja Date: 14:00-16:00 on April 17 (Monday) Place: 1901(19F), NII https://www.nii.ac.jp/about/access/ Title and Abstract: see below

Best Regards, Ken Satoh ====================================================== Past, present, and future of deontic logic

Abstract. I will give an overview of deontic logic, based on the main challenges addressed in the area. In the past the main challenges were contrary-to-duty reasoning and conflicting norms, which led to preference-based semantics and a modal logic approach. Presently the focus is on Jorgensen's dilemma and the logic of permissive and constitutive norms, which led to norm based semantics. In the future I expect more focus on agent centered issues such as knowledge based obligation, moral luck, procrastination, multiagent miner scenarios, imperatives, and game based semantics.

Paper. GABRIELLA PIGOZZI AND LEENDERT VAN DER TORRE, Multiagent Deontic Logic and its Challenges from a Normative Systems Perspective. Handbook of normative multiagent systems, to appear. College Publications.

http://icr.uni.lu/leonvandertorre/papers/HNMAS17.pdf

Bio. Leon van der Torre joined the University of Luxembourg as a full professor for Intelligent Systems in 2006. He developed the BOID agent architecture (with colleagues from Vrije Universiteit Amsterdam), input/output logic (with David Makinson) and the game-theoretic approach to normative multiagent systems (with Guido Boella). He is an editor of the handbook of deontic logic and normative systems (first volume 2013, second volume in preparation), editor of the handbook on formal argumentation (in preparation), editor of the handbook on normative multi agent systems (in preparation), deontic logic corner editor of Journal of Logic and Computation, and member of editorial board of Logic Journal of the IGPL, the IfCoLog Journal of Logics and their Applications, and the EPiC series in Computer Science. Moreover he is coordinator of the Horizon2020 Marie Curie RISE Network “Mining and Reasoning with Legal Texts” (MIREL, 2016-2019).

Deontic logic. The past. The first volume of the handbook of deontic logic and normative systems [2013] explains that traditional modal deontic logic has been criticized for several reasons, and the past twenty years have seen the development of several alternatives to the traditional modal approach such as input/output logic, non-monotonic approaches, logic programming based approaches, update semantics, causal deontic logic, algebraic approaches, etc. Nevertheless, the traditional modal approach is still often referred to as "standard" deontic logic. The present. The area of deontic logic is currently split into two main traditions. The first one is centered in US and linguistics / philosophy and follows the traditional modal approach along three main developments: System KD [Von Wright 1951], preference based semantics [Hansson 1969,Lewis 1973], and the general theory of modality based on modal base and ordering source [Kratzer 1981]. The second tradition is more centered in EU and legal philosophy / computer science and is based also on three main developments, namely normative systems [Alchourron & Bulygin 1971], non-monotonic logic [Horty 1991] , and norm based semantics [Makinson 1999]. The future. I expect these two traditions to merge in the coming years. The past five years researchers in these two traditions have started to realize that these two traditions are much more similar than previously understood. Many of the proposed advantages of the alternative approach have already been handled by developments in the traditional approach [Horty 2014]. The similarity of the formal systems in both traditions has been the topic of two ESSLLI courses [Condoravdi and van der Torre 2014, 2016].