192.130 Deontic Logic for Normative Reasoning
This course is in all assigned curricula part of the STEOP.
This course is in at least 1 assigned curriculum part of the STEOP.

2023S, VU, 2.0h, 3.0EC


  • Semester hours: 2.0
  • Credits: 3.0
  • Type: VU Lecture and Exercise
  • Format: Hybrid

Learning outcomes

After successful completion of the course, students are able to

  • Understand the mainstream formalisms in deontic logic for normative reasoning
  • Understand and discuss some of the main problems encountered in deontic logic
  • Use deontic logic to formalize legal or ethical reasoning
  • Communicate the basic concepts of deontic logic and their relevance for computer science and AI
  • Get a better insight on how deontic logic can be relevant for their own work

Subject of course

Deontic logic deals with obligation, permission and related normative concepts. It has become increasingly relevant for domains where it is necessary to distinguish between what is the case and what ought to be the case. In multi-agent systems and AI, it is viewed as instrumental in the design of a fully autonomous system,  able to reason about the lawfullness of its own behavior, and make ethical decisions. In legal informatics, it provides effective and general means for the automation of normative reasoning  processes based on legal knowledge bases. In philosophy, it provides a means of precise description of meaning, and helps tounderstand the nature of normative (e.g. ethical) reasoning, whose very possibility has been questioned. In linguistics it is a powerful tool for the semantic analysis of deontic modalities like ``must" or ``may'', thus allowing to draw meaning from texts
containing these modalities.

The course will cover the fundamentals of deontic logic, which emphasis on their semantics.

Two research traditions have dominated the landscape of deontic logic, one drawing on methods from modal logic, and the other drawing on methods from AI and rule-based systems.  This course will introduce to three frameworks representative of these two research traditions: monadic deontic logic (MDL), dyadic deontic logic (DDL), and input/output (I/O) logic. We will describe their language, semantics, axiom systems,and gives soundness and completeness theorems. We will also introduce students to some of the main topics discussed in deontic logic, including reasoning about norm violation and conflicts. If time allows the course will provide a glimpse of normative automated reasoning (Isabelle/HOL).

This is primarily meant as a logic course.  However, it will also introduce to topics in philosophy of norms and in the philosophy of language, of direct relevance to the course.

The course will be based on a textbook co-written by the lecturer and Prof. Dr. van der Torre (University of Luxembourg), Introduction to Deontic Logic and Normative Systems (College Publications, UK, 2018). The textbook is freely available on the publisher's website.

Teaching methods

The course is organized in on-line lectures, homework and exercise sessions 

Blocked course over 12 days, with one lecture per day at 4 pm Vienna Time / 10 am Tufts time

Scheduled for 1-13 June 2023. 




Mode of examination


Additional information


  • 1.6.2023:  Intro + MDL, Anderson's reduction
  • 2.6.2023:  paradoxes + neighborhood semantics
  • 5.6.2023:  practicals          
  • 6.6.2023:  DDL 1
  • 7.6.2023:  DDL 2
  • 8.6.2023: no lecture (bank holiday) 
  • 9.6.2923:   IOL 1
  • 12.6.2023: IOL 2
  • 13.6.2023: practicals
  • 16.6.2023: practicals (exact day to be discussed)




Examination modalities

Final exam to be held on-line (60%)

Homework (40%)

Course registration

Begin End Deregistration end
21.02.2023 11:00

Registration modalities

Register in advance for this meeting:


After registering, you will receive a confirmation email containing information about joining the meeting.



No lecture notes are available.

Previous knowledge

 Propositional logic. Knowledge of modal logic is a plus, but not required.

Preceding courses