## Belief, Desire, and Rational Choice (Autumn 2022)

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. The second part studies formal models of value or desire, drawing on utility theory in economics and value theory in philosophy. The third part looks at how beliefs and desires guide rational action, going through some basic issues in Bayesian decision theory.

No prior knowledge of the material is expected, beyond familiarity with elementary arithmetic and propositional logic.

### Course Organiser

Dr Wolfgang Schwarz (wolfgang.schwarz@ed.ac.uk)

Office hours: Friday 11:00--12:00 and by appointment

My office is room 8.06 in 40 George Square

### Course Secretary

Peter Cruickshank (philinfo@ed.ac.uk)

### Classes

**Undergraduate seminars:**

Monday 13:10--14:00, Dugald Stewart Building, room 1.20

Wednesday 13:10--14:00, Dugald Stewart Building, room 1.17

**Postgraduate seminars:**

Monday 10:00--10:50, Forresthill, room 1.B15

Wednesday 10:00--10:50, Appleton Tower, room 2.11

### Format and Assessment

The course is based on an online textbook, whose chapters will appear in the syllabus below. (You can take a look at the last version of the full textbook at wolfgangschwarz.net/bdrc/bdrc.pdf, but the content will change this year, so do pay attention to what I upload to the syllabus!)

You are expected to work through each week's chapter *in advance*,
before the Monday seminar. Each chapter contains exercises, which you should try
to answer (on paper, with your student number at the top). I will collect your
answers at the start of the seminar on Monday. The exercises determine 50% of
your mark.

The remaining 50% of your mark are based on a final essay of up to 1500 words, due by Thursday, 8 December, by 12 noon (UK time). Suggestions for essay questions can also be found in the textbook.

### Readings

The only required reading is the online textbook, whose (revised) chapters will appear in the syllabus below.

Supplementary reading for the whole course:

- Jonathan Weisberg: Odds and Ends (2021)
- Katie Steele and H. Orri Stefansson: "Decision Theory" (2020)
- Lara Buchak: "Decision Theory" (2016)
- Michael Strevens: Notes on Bayesian Confirmation Theory (2017)

### Literature access

The syllabus below contains pointers to further texts that you are encouraged to read. If a text is not freely available online, you can find it in a secret folder, whose address will be revealed in class. If you've forgotten the address of that folder, send me an email.

## Syllabus

### Week 1 (19/09): Overview

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

Core reading: **Chapter 1 (PDF).**

Background reading:

- Alan Hajek: "Pascal's wager" (2017)
- 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 (26/09): Belief as probability

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

Core reading: **Chapter 2 (PDF).**

Background reading:

- Ian Hacking: An Introduction to Probability and Inductive Logic, ch.s 3-7 (2001)
- Jonathan Weisberg: Odds and Ends, ch.s 5-9 (2019)
- Brian Skyrms: "Zeno's paradox of measure" (1983)
- Zeynep Soysal, "A metalinguistic and computational approach to the problem of mathematical omniscience" (2022)

### Week 3 (03/10): Probabilism

The betting interpretation of belief; Dutch Book arguments; declining marginal utility; comparative credence.

Core reading: **Chapter 3 (PDF).**

Background reading:

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

### Week 4 (10/10): Further constraints on rational belief

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

Core reading: Chapter 4 (to be released).

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 (17/10): Utility

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

Core reading: Chapter 5 (to be released).

Background reading:

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

### Week 6 (24/10): Preference

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

Core reading: Chapter 6 (to be released).

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 (31/10): Separability

The composition of value; additivity; discounting.

Core reading: Chapter 7 (to be released).

Background reading:

- Paul Weirich: "Multi-Attribute Approaches to Risk" (2012)
- Johanna Thoma: "Temptation and preference-based instrumental rationality" (2018)
- John Broome: "General and Personal Good: Harsanyi's Contribution to the Theory of Value" (2015)

### Week 8 (07/11): Why maximize expected utility?

Arguments for the MEU principle; dynamic decision theory; risk; localism.

Core reading: Chapter 8 (to be released).

Background reading:

- Robin P. Cubitt: "Rational Dynamic Choice and Expected Utility Theory" (1996)
- Paul Weirich: "Expected Utility and Risk" (1986)
- Lara Buchak: "Redescription" (2014)

### Week 9 (14/11): Evidential and Causal Decision Theory

Newcomb's problem; EDT vs CDT.

Core reading: Chapter 9 (to be released).

Background reading:

- Arif Ahmed: Introduction to
*Newcomb's Problem*(2018) - 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 (21/11): Game theory

Core reading: Chapter 10 (to be released).

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 (28/11): Bounded rationality

Core reading: Chapter 11 (to be released).

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" (2019)