Belief, Desire, and Rational Choice (Spring 2020)

This course is an introduction to formal models of belief, desire, and rational choice. It has roughly three parts. The first introduces the core ideas of Bayesian epistemology, where belief is treated as an attitude that comes in degrees. In the second part, we turn to formal models of desire, drawing on utility theory in economics and value theory in philosophy. We will also look at some connections between rational belief and desire. The third part takes a closer look at decision theory, which formalises the intuition that rational agents do what they believe will bring them closer to satisfying their desires.

No prior knowledge of the material is expected. Familiarity with basic propositional logic will be helpful.

Classes consist of a one-hour lecture plus a one-hour tutorial.

Course organiser

Dr Wolfgang Schwarz (

Office hour: Thursday 15:00-16:00 and by appointment

My office is room 6.02, Dugald Stewart Building.

Course administrator

Ann-Marie Cowe (


Lecture notes with exercises will be made available each week, and are the only required reading.

If you want to look ahead, here are the notes from last year (PDF). The content might change for this year, however, so pay attention to what I upload in the syllabus below!

Some background reading:


  • Lecture: TBD
  • Tutorial Group 1: TBD
  • Tutorial Group 2: TBD


The lecture notes for each week will contain exercises. You should try to answer all of them and hand in your solutions (on paper, with your student number at the top) at the start of the next lecture. I will mark your submissions for each week on a scale from roughly 30 to 90; the average of your scores will be converted into 50% of your final grade.

The question mark rule: If you write a question mark next to an answer on an exercise sheet (even if the answer is empty), I will give you a 20% higher mark if you're wrong and a 20% lower mark if you're right.

The lecture notes also contain essay questions. At the end of the term, you should choose one of these to write a short essay of 1500 words. Your mark for the essay determines the other 50% of your grade.

Literature access

You can find all the readings that aren't links in a secret folder. If you've forgotten the address of that folder, send me an email.


Week 1: Overview

How beliefs and desires are related to choice; why beliefs and desires are graded; the difference between conceptual analysis and model-building.

Background reading:

Week 2: Belief as probability

Basic rules of probability; Bayes' theorem; some applications.

Background reading:

Week 3: Probabilism

Why degrees of beliefs should conform to the principles of probability theory.

Background reading:

Week 4: Further constraints on rational belief

Belief and perception; conditionalization; the Principle of Indifference; probability coordination.

Background reading:

Week 5: Utility

Two conceptions of utility; sources of utility; utility and credence; the formal structure of utility.

Background reading:

  • Simon Blackburn: "Game Theory and Rational Choice", chapter 6 of Ruling Passions (1998)
  • John Broome: "Utility" (1991)

Week 6: Preference

The ordinalist challenge; deriving utility measures from a preference ordering.

Background reading:

Week 7: Separability

The composition of value; additivity; discounting.

Background reading:

Week 8: Risk

Why maximize expected utility? MEU and risk; localism.

Background reading:

  • James Dreier: "Rational Preference: Decision Theory as a Theory of Practical Rationality" (1996)
  • Paul Weirich: "Expected Utility and Risk" (1986)
  • Lara Buchak: "Redescription" (2014)

Week 9: Evidential and Causal Decision Theory

Newcomb's problem; EDT vs CDT.

Background reading:

Week 10: Game theory

Background reading:

Week 11: Bounded rationality

Background reading: