PHI 533 Decision Theory:

Bayesian perspectives on expressivism, fragmentation, and disagreement

Graduate seminar, Spring 2008. Open to graduate students only.

Adam Elga (follow link for contact information, office hour). Class meeting time: Mondays 2:00-4:50 Mondays. Location: Marx Hall 201

Seminar description: We will study disagreements over beliefs, values, and preferences from a Bayesian point of view. Topics include expressivism about rationality and about chance, belief and desire fragmentation and logical omniscience, the "agreeing to disagree" theorem, epistemic permissiveness and the uniqueness thesis, the problem of disagreement, the problem of contingency, and desiring at will.

Readings: To access the readings (all available electronically, as linked below), you will need a userid (the userid is "guest") and a password (announced in class). If you would like to preview the readings, please email

Note: In many cases, only a subsection of the linked reading is required. In those cases, the required page range is listed after the reading itself.


February 11: Agustin Rayo, MIT

Feb 25: Andrew Egan, University of Michigan

March 10: Roger White, MIT

March 24: Ernest Sosa, Rutgers University

March 31: John Collins, Columbia University

April 14: Robin Hanson, George Mason University

April 21: Daniel Garber, Princeton University

Expressivism about rationality and values

Mon Feb 04


Mon Feb 11

Guest session leader: Agustin Rayo

Topic: Fragmentation and logical omniscience

Stalnaker, Robert. The problem of logical omniscience I.

Stalnaker, Robert. Inquiry. Chapter 4

Stalnaker, Robert. Inquiry. Chapter 5 pp. 79-87.


Field, Hartry. Review of Inquiry, sections 2-3.

Lewis, David. Radical interpretation.

Mon Feb 18

Fundamental methods for reasoning.

Field, Hartry. Apriority as an evaluative notion, 130-134 and the appendix.

Kripke. Wittgenstein on rules and private language. Chapter 2: The Wittgenstinian paradox. 7-37

Chomsky. Knowledge of language. Chapter 4: Questions about rules. 223-225, 236 (last paragraph) - 240.

Mon Feb 25

Guest session leader: Andrew Egan, University of Michigan

Gibbard, Alan. Wise choices, apt feelings. Chapter 5: Normative logic

Gibbard, Alan. Normative objectivity


Gibbard, Alan. Moral Judgment and the Acceptance of Norms

Gibbard, Alan. Wise choices, apt feelings. Chapter 9: Normative authority

Egan, Andy. De Gustibus Non Disputandum Est (at Least, Not Always)

Mon Mar 03

Gibbard, Alan. Normative objectivity

Smith, Michael. Evaluation, Uncertainty and Motivation


Wedgwood, Ralph. The Nature of Normativity. Chapter 2.

Brown Electronic Article Review Service Symposium on Smith

Mon Mar 10

Guest leader: Roger White

Are unsharp responses to evidence ever perfectly rational?

White, Roger. Evidential symmetry and mushy credence Manuscript. Read from p. 8 to the end.

van Fraassen, Bas. Vague expectation value loss

Elga, Adam. Subjective probabilities should be sharp. Manuscript. Note: I'm not sure if I believe this argument any more...


Christensen, David. Clever Bookies and Coherent Beliefs

Mon Mar 24

Guest leader: Ernest Sosa

Boghossian, Paul. Fear of Knowledge: Against Relativism and Constructivism. Chapter 7

Sosa, Ernest. Reflective Knowledge Read the prefatory material and section 5 of Chapter Ten, and everything in Chapter Eleven, except for the concluding section, on Descartes. The omitted materials would then be helpful as background reading, but are not essential.


Mon Mar 31

Guest leader: John Collins

Aumann, Robert. Agreeing to disagree

Collins, John. How We Can Agree to Disagree

Mon Apr 07

Christensen, David. Epistemology of Disagreement: the Good News, pp. 199-203

Kelly, Tom. Peer Disagreement and Higher Order Evidence, pp. 12-17, 29-34

Elga, Adam. Reflection and disagreement, pp. 17-20

Mon Apr 14

Guest leader: Robin Hanson

Hanson, Robin and Cowen, Tyler. Are Disagreements Honest?

Hanson, Robin. Uncommon Priors Require Origin Disputes

Mon Apr 21

The problem of contingency

Guest co-leader: Daniel Garber

Sher, George. But I could be wrong

Cohen, G. A. Chapter 1: Paradoxes of conviction of If you're an egalitarian, how come you're so rich?. Pages 7-13.

Mon Apr 28

Constraints on desiring at will. Expressivism about values.

Egan, Greg. Quarantine. London : Legend, 1992. pp. 73--75 (first 3 pages of chapter 5). Explanatory note: the selected passage occurs shortly after the narrator, a detective, has been captured by his enemy, BDI. Rather than kill him, BDI installs a "loyalty mod" in his brain -- a device that changes his priorities in ways that the passage reveals.

Egan, Greg. Axiomatic, first three pages. In Axiomatic (Harper Prism, December 1997).

Millgram, Elijah. Practical Induction. Chapter 2.

Shoemaker, S. Desiring at will (and at pill): a reply to Millgram pp. 26-29.


Topic: TBA

Optional background readings

Stalnaker. The problem of logical omniscience II.

van Inwagen, Peter. "It is Wrong, Always, Everywhere, and for Anyone, to Believe Anything, Upon Insufficient Evidence". Pages 137-143.

Sunstein, Cass. Deliberative Trouble? Why Groups Go to Extremes Yale Law Journal 110(1) October 2000. Pages 71-90.

Maher, Patrick. Betting on theories. Chapter 1.

Maher, Patrick. Betting on theories. Chapter 4. Section 4.4.

Adam Elga | Princeton University