Skip to main content

Modal Logic (PH341-15)


This module is not running in 2017-18.


Modal operators are expressions such as it is necessary/possible that, in the future/past, it is obligatory/ permissible that, it is known/believed that, it is provable that, it is true after performing computational operation α that which when prefixed to a declarative sentence can be understood to modify the way in which it is true. Modal logic – i.e. the study of formal systems for reasoning about such operators – finds far reaching applications in philosophy, computer science, and mathematical logic.

We will begin studying axiom and tableau proof systems for some common propositional and first-order modal logics. We next consider a semantic theory for these systems in the form of Kripke (or possible world) models relative to which we will prove the soundness and completeness of the logics in question. Here are some topics we will touch on along the way: rigid designation and the de re/de dicto distinction (philosophy of language), possibilist versus actualist quantification (metaphysics), logical omniscience and bounded rationality (epistemology), intuitionism, formal versus informal provability and Gödel’s Incompleteness Theorems (mathematical logic), using modal logic to reason about distributed systems and program correctness (computer science).


By the end of the module the student should be able to: 1) demonstrate knowledge of formal systems of modal logic (proof theory and semantics); 2) understand the relationships between these formal systems and questions, e.g., about the nature of modality, identity, or conditionals; 3) use and define concepts with precision, both within formal and discursive context.


In this module students must attend 3 hours of lectures and a one hour seminar per week attended by all students.

Lectures for 2016-17



This module is formally assessed in the following way:

  • Assessed exercises (15% of module)
  • 2-hour examination (85% of module)

Course materials

From October 2016 course materials will be available on Moodle. Simply sign in and select the module from your Moodle home page.

Please note you must be regisitered for the module on eMR in order to access the relevant page.

Module Tutor:

Dr Adam Epstein

A dot L dot Epstein at warwick dot ac dot uk