Welcome to the course Philosophical Logic! It is given during the summer semester 2026 at LMU Munich as part of the Master in Logic and Philosophy of Science. (Past editions: summer 2023, 2024, 2025, and previously at the University of Amsterdam.)
Motivation
Often, what is understood by ‘logic’ is classical logic (either classical propositional logic or classical first-order logic). Its typical features are, for example, that a sentence p is either true or false and that not not p is the same as p. In many situations, though, simply assuming classical logic is not appropriate. Such situations arise, as we will see, in philosophy and neighboring disciplines (like mathematics, computer science, and linguistics). For example, when reasoning with: vague concepts, incomplete or inconsistent data, conditionals (i.e., ‘if, then’ sentences), and what it means to be true. The course will be about exploring different logics to model these (and other) phenomena. A focus of the course is on using both algebraic and state-based (or ‘possible world’) semantics to mathematically describe the meaning of these different logics.
General information
The instructor of the seminar is me, Levin Hornischer. During the semester, we meet on Thursdays from 14:00 to 16:00 in room 028 (Ludwigstr. 31). Below you find a schedule of when we cover which topic.
Lecture Notes
You find the latest edition of the lecture notes in this file: phillog.pdf. They are updated as the course progresses.
Formalities
All the organizational details for the course are described in this file: formalities.pdf.
Schedule
The schedule below describes in which week we will cover which material. The sections refer to the lecture notes. The exercises are recommended to do for the next session.
| Week | Week Date | Chapter | Lecture | Exercises |
|---|---|---|---|---|
| 1 | 16 Apr | 1-2 | until and including sec. 2.2 | Recap sec. 2.2 and do exercises therein |
| 2 | 23 Apr | 2 | until beginning of 2.4 (‘Boolean algebras formally’ only briefly, TBC) | Ex. 2.20, 2.21, and 2.22. |
| 3 | 30 Apr | TBA | ||
| 4 | 7 May | TBA | ||
| 5 | 21 May | TBA | ||
| 6 | 28 May | TBA | ||
| 7 | 11 Jun | TBA | ||
| 8 | 18 Jun | TBA | ||
| 9 | 25 Jun | TBA | ||
| 10 | 2 Jul | TBA | ||
| 11 | 9 Jul | TBA | ||
| 12 | 16 Jul | - | Exam |
Assessment
There will be a written exam in the last session, which determines your final grade. The exam will be open book. See the formalities above for more details on the exam modalities. An example exam will be uploaded here in due course.