## 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 (wolfgang.schwarz@ed.ac.uk)

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

My office is room 6.02, Dugald Stewart Building.

### Course administrator

Ann-Marie Cowe (philinfo@ed.ac.uk)

### Readings

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:

- Lara Buchak: "Decision Theory" (2016)
- Katie Steele and H. Orri Stefansson: "Decision Theory" (2015)
- Michael Strevens: Notes on Bayesian Confirmation Theory (2017)

#### Classes

- Lecture: TBD
- Tutorial Group 1: TBD
- Tutorial Group 2: TBD

## Assessment

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.

## Syllabus

### 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:

- Alan Hajek: "Pascal's wager" (2017)
- James Joyce: "Decision Problems", chapter 2 of
*The Foundations of Causal Decision Theory*(1999) - Ansgar Beckermann: "Is there a problem about intentionality?" (1996)
- Alisa Bukolich: How scientific models can explain (2011)
- Mark Colyvan: Idealisations in normative models (2013)

### Week 2: Belief as probability

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

Background reading:

- Ian Hacking: An Introduction to Probability and Inductive Logic, ch.s 3-7 (2001)
- Brian Skyrms: "Zeno's paradox of measure" (1983)
- Robert Stalnaker: "The problem of logical omniscience I" (1991)

### Week 3: Probabilism

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

Background reading:

- Alan Hajek: "Dutch Book Arguments" (2008)
- Susan Vineberg: "Dutch Book Arguments" (2016)
- Peter Fishburn: "The Axioms of Subjective Probability" (1986)

### Week 4: Further constraints on rational belief

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

Background reading:

- Ian Hacking: An Introduction to Probability and Inductive Logic (2001)
- Christopher Meacham: "Impermissive Bayesianism" (2014)
- Nick Bostrom: "The Doomsday Argument, Adam & Eve, UN++, and Quantum Joe" (2001)

### 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:

- Samir Okasha: "On the Interpretation of Decision Theory" (2016)
- Daniel Hausman: "Mistakes about Preferences in the Social Sciences" (2011)
- Peter Fishburn: "Utility and Subjective Probability" (1994)

### Week 7: Separability

The composition of value; additivity; discounting.

Background reading:

- Tomasz Żuradzki: "Time-biases and Rationality: The Philosophical Perspectives on Empirical Research about Time Preference" (2016)
- John Broome: "Utilitarianism and Expected Utility" (1987)

### 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:

- Arif Ahmed: "Causation and Decision" (2010)
- Jack Spencer and Ian Wells: "Why Take Both Boxes?" (2017)
- David Lewis: "Causal Decision Theory" (1981)
- Frank Arntzenius: "No Regrets, or: Edith Piaf Revamps Decision Theory" (2008).

### Week 10: Game theory

Background reading:

- Brian Weatherson:
*Lecture Notes on Decision Theory*, ch.s 19-27 (2015) - Philip Pettit and Robert Sugden: "The Backward Induction Paradox" (1989)
- Brian Skyrms: "Game Theory, Rationality and Evolution of the Social Contract" (2000)

### Week 11: Bounded rationality

Background reading:

- Samuel Gershman et al: "Computational rationality: A converging paradigm for intelligence in brains, minds, and machines" (2015)
- Daniel Kahneman: "A Perspective on Judgment and Choice: Mapping Bounded Rationality" (2003)
- Saemus Bradley: "Imprecise Probabilities" (2014)