Decision Theory: Self-locating Belief, Anthropic Reasoning, and Skepticism (PHI 533), Fall 2025

Instructor: Adam Elga
Meeting time: Fridays 1:00-3:50pm
Meeting location: Wooten Hall 201
Grading basis: */AUD

Description

Is there a distinctive type of “self-locating” uncertainty which concerns who one is or what time it is (as opposed to what the world is objectively like)? If so, how should such uncertainty be represented? How should one update one’s self-locating probabilities based on new evidence? Should an “anthropic principle” or “observation selection effect” influence our evaluation of cosmological theories? Is the apparent fine-tuned nature of the physical constants evidence for multiple universes? For the existence of God? Does a principle of indifference show that you should think you are a randomly formed “Boltzmann brain”?

Guest session-leaders will include Christopher Meacham, Roger White, Sinan Dogramaci, and Miriam Schoenfield. The seminar is open to graduate students only.

Units

Students in the Princeton graduate philosophy program can earn a unit associated with the seminar by (1) attending, (2) giving a presentation on one of the readings (arrange this with me in advance), and (3) writing a term paper (target length: 6000 words; due 5pm on Friday December 12, 2025).

Presentations

If you will be consistently attending the seminar and would like to give a short presentation on one of the readings, please let me know. If you are giving a presentation, please follow these guidelines.

Note on readings

Schedule and readings are subject to change. For each week, required readings (if any) are listed first, followed by optional background readings. Please note:

When I list a reading as “optional”, I mean it: I won’t expect anyone to have even looked at any of the optional readings.
In many cases only a portion of a reading might be assigned, indicated immediately after the reading. That means I won’t expect anyone to have even looked at unassigned portions of the listed readings.

Schedule and readings

[2025-09-05 Fri] Why think we need self-locating beliefs?

Lewis, D. (1983). Attitudes De Dicto and De Se. In D. Lewis (Ed.), Philosophical Papers Volume I. Oxford University Press. https://doi.org/10.1093/0195032047.003.0010
Sections 1-11

Stalnaker, R. C. (2019). Modeling a Perspective on the World. In R. C. Stalnaker (Ed.), Knowledge and Conditionals: Essays on the Structure of Inquiry. Oxford University Press. https://doi.org/10.1093/oso/9780198810346.003.0005
Sections 1-2

Optional background:

Egan, A., & Titelbaum, M. G. (2022). Self-Locating Beliefs. In E. N. Zalta & U. Nodelman (Eds.), The Stanford Encyclopedia of Philosophy (Winter 2022). Metaphysics Research Lab, Stanford University. https://plato.stanford.edu/archives/win2022/entries/self-locating-beliefs/
Sections 1-2

[2025-09-12 Fri] Why think we don’t need self-locating beliefs?

Magidor, O. (2015). The Myth of the De Se. Philosophical Perspectives, 29(1), 249–283. https://doi.org/10.1111/phpe.12065
Introduction and Sections 1.1-1.7

Cappelen, H., & Dever, J. (2013). Indexicality, the De Se, and Agency. In H. Cappelen & J. Dever (Eds.), The Inessential Indexical: On the Philosophical Insignificance of Perspective and the First Person. Oxford University Press. https://doi.org/10.1093/acprof:oso/9780199686742.003.0003
Introduction and Sections 3.1-3.6

[2025-09-19 Fri] Observation selection effects

Ćirković, M. M., Sandberg, A., & Bostrom, N. (2010). Anthropic Shadow: Observation Selection Effects and Human Extinction Risks. Risk Analysis, 30(10), 1495–1506. https://doi.org/10.1111/j.1539-6924.2010.01460.x
Sections 1-2

Thomas, T. (2024). Dispelling the Anthropic Shadow (Working Paper 20–2024; Global Priorities Institute Working Paper Series). Global Priorities Institute. https://globalprioritiesinstitute.org/wp-content/uploads/Dispelling-the-Anthropic-Shadow-Teruji-Thomas.pdf
Sections 1-4

[2025-09-26 Fri] Updating self-locating probabilities: introduction, cases, bullets

Presenter: Lingzhi

Titelbaum, M. (2017). Self-Locating Credences. In A. Hájek & C. Hitchcock (Eds.), The Oxford Handbook of Probability and Philosophy. Oxford University Press. https://doi.org/10.1093/oxfordhb/9780199607617.013.34
Sections 31.1 - 31.5

Isaacs, Y., Hawthorne, J., & Russell, J. S. (2022). Multiple Universes and Self-Locating Evidence. Philosophical Review, 131(3). https://doi.org/10.1215/00318108-9743809
Section 4

Adelstein, M. (2024). Alternatives to the self-indication assumption are doomed. Synthese, 204(1), 23. https://doi.org/10.1007/s11229-024-04686-w
Sections 1,2,3,5

Optional background:

Carlsmith, J. (2022). SIA vs. SSA. Chapter 1 of A stranger priority? Topics at the outer reaches of effective altruism [PhD Dissertation, University of Oxford]. https://ora.ox.ac.uk/objects/uuid:bf57403d-1e4c-442a-bfe7-0366644ac234
Sections VI-IX

Moss, S. (2012). Updating as Communication. Philosophy and Phenomenological Research, 85(2), 225–248. https://doi.org/10.1111/j.1933-1592.2011.00572.x

[2025-10-03 Fri] Updating self-locating probabilities: varieties of conditionalization

Guest session-leader: Christopher Meacham

Meacham, C. J. G. (2007). Unravelling the Tangled Web: Continuity, Internalism, Non-Uniqueness and Self-Locating Beliefs. In T. S. Gendler & J. Hawthorne (Eds.), Oxford Studies in Epistemology: Volume 3 (p. 86). Oxford University Press UK. https://philarchive.org/rec/MEAUTT
Read the whole article except: it’s OK to skip sections 4.2.2, 5.1, 5.2.

Meacham, C. J. G. (2016). Ur-Priors, Conditionalization, and Ur-Prior Conditionalization. Ergo, 3. https://doi.org/10.3998/ergo.12405314.0003.017
Read the whole article except: it’s OK to skip sections 4.1.1 and 4.1.2.

[2025-10-10 Fri] Fine-tuning argument for the existence of god

Presenter: Noah

Weisberg, J. (2010). A note on design: What’s fine-tuning got to do with it? Analysis, 70(3), 431–438. https://doi.org/10.1093/analys/anq028

Roberts, J. T. (2012). Fine-Tuning and the Infrared Bull’s-Eye. Philosophical Studies, 160(2), 287–303. https://doi.org/10.1007/s11098-011-9719-0

Hawthorne, J., & Isaacs, Y. (2018). Fine-Tuning Fine-Tuning. In M. A. Benton, J. Hawthorne, & D. Rabinowitz (Eds.), Knowledge, Belief, and God: New Insights in Religious Epistemology. Oxford University Press. https://doi.org/10.1093/oso/9780198798705.003.0008
Sections 7.5-7.6.6

[2025-10-17 Fri] No class (Fall Break)

[2025-10-24 Fri] Fine-tuning argument for the existence of multiple universes

Presenter: Sagar

Isaacs, Y., Hawthorne, J., & Russell, J. S. (2022). Multiple Universes and Self-Locating Evidence. Philosophical Review, 131(3). https://doi.org/10.1215/00318108-9743809
Sections 5-6

Meacham, C. J. G. (Forthcoming). Fine-Tuning, Multiple Universes, and Self-Locating Beliefs. In D. Rubio & K. J. Kraay (Eds.), The Blackwell Companion to Philosophy and the Multiverse. Blackwell. https://philarchive.org/rec/MEAFMU
Sections 1-6

Optional background:

White, R. (2000). Fine-Tuning and Multiple Universes. Noûs, 34(2), 260–276. https://doi.org/10.1111/0029-4624.00210

Friederich, S. (2019). A New Fine-Tuning Argument for the Multiverse. Foundations of Physics, 49(9), 1011–1021. https://doi.org/10.1007/s10701-019-00246-2

Arntzenius, F., & Dorr, C. (2017). Self-Locating Priors and Cosmological Measures. In K. Chamcham, J. Barrow, S. Saunders, & J. Silk (Eds.), The Philosophy of Cosmology (pp. 396–428). Cambridge University Press. https://philarchive.org/rec/DORSPA-4
Sections 1-3

[2025-10-31 Fri] Simulation argument, cognitive instability, and skepticism

Thomas, T. (2024). Simulation Expectation. Erkenntnis. https://doi.org/10.1007/s10670-024-00901-9
Sections 1 - 3.4

Lewis, P. J., & Fallis, D. (2023). Simulation and self-location. Synthese, 202(6), 180. https://doi.org/10.1007/s11229-023-04413-x

Optional background:

Elga, A. (2025). Boltzmann brains and cognitive instability. Philosophy and Phenomenological Research, 111(1), 127–136. https://doi.org/10.1111/phpr.70014

[2025-11-07 Fri] Persuasion, agreement, and self-location

Guest session-leader: Roger White

White, R. “How to persuade yourself of (almost) anything.” Manuscript has been posted to Canvas under “Files”. (Dr. White also may bring to class an experimental prototype of the persuasion machine he has designed.)

[2025-11-14 Fri] Problem of Boltzmann brains

Guest session-leaders: Sinan Dogramaci and Miriam Schoenfield

Dogramaci, S., & Schoenfield, M. (2025). Why I Am Not a Boltzmann Brain. Philosophical Review, 134(1), 1–33. https://doi.org/10.1215/00318108-11591068
Prioritize sections 1-2.

Optional background:

Dogramaci, S. (2025). Boltzmannian Skepticism about the Past Hypothesis. Manuscript has been posted to canvas under “Files”.

Dogramaci, S. (2020). Does my total evidence support that I’m a Boltzmann Brain? Philosophical Studies, 177(12), 3717–3723. https://doi.org/10.1007/s11098-019-01404-y

[2025-11-21 Fri] Problem of Boltzmann brains, continued

Presenter: Chris

Hughes, C. (2025). Boltzmann brains and self-locating evidence. Manuscript has been posted to canvas under “Files”.
Prioritize sections 1-6.

Elga, A. (2025). Boltzmann brains and cognitive instability. Philosophy and Phenomenological Research, /111/(1), 127–136. https://doi.org/10.1111/phpr.70014

[2025-11-25 Tue] Principle of Indifference (topic subject to change)

Note: special meeting on Tuesday rather than Friday.
Presenter: Sebastian

Lando, T. (2021). Evidence, ignorance, and symmetry. Philosophical Perspectives, 35(1), 340–358. https://doi.org/10.1111/phpe.12151

Guidelines for giving a presentation

At least one week before your presentation, please email me to inform me which of the assigned readings (or portion of readings) you plan to present on. If there is more than one presenter that week, please coordinate between you to avoid overlap.
Plan two or three “discussion units”. A discussion unit consists of your (a) giving a 5-minute micro-talk setting the stage or raising a problem, (b) asking a question or posing a challenge for the class to answer or complete in pairs (that results in a concrete response from each pair), (c) bringing the class together after 5-10 minutes of in-pairs discussion and leading a full-class discussion on the question or issue. I encourage but do not require you to write a simple diagram or picture on the board during the micro-talk.
You do not have to understand everything perfectly. It is OK if part of your presentation involves expressing focused puzzlement about some aspect of the readings.
Please prepare a short handout outlining the presentation and stating the core points and questions (and including a header with your name, the date, and “PHI 533 handout”). Either bring copies of the handout for everyone (and also email me a copy right after class), or if you email me the handout at least 24 hours before the start of class I will make copies and bring them.