Metaphysics: Material Objects

April 30th:

  • Goodbye!
  • Thanks to all of you for helping to make this course worthwhile. I appreciate the work that many of you put into the course, especially the problem sets, and I hope you ended up feeling like you got something out of the whole experience.
  • Here are the final paper topics.
  • Let me again encourage you to look at Jim Pryor's guidelines on writing philosophy papers.
  • There's a big load of old problem sets that people have never picked up. I've decided to deal with the problem by putting them in envelopes in a folder with the name of the class on it in the blue filing cabinet in the philosophy department library (503 Main Building). Right now (April 23rd) the list of people who have something to pick up is as follows (this includes some people who dropped out of the course): Becky Alford, Joseph Azam, Jonathan Barnes, Katherine Carroll, Sarah Cline, Jason Danforth, Isaiah Juste, Kenneth Lee, Amit Malkani, Haroon Moghul, Mike Russo, James Rodriguez, Daniel Sapir, Justin Savino-Sullins, Clare Smith, Jessie Strand. In the future I'll put corrected problem sets there immediately after handing them out in class.

Course Description

Our starting point in this course will be the paradoxes of material constitution. For example, suppose that I have just taken some clay and shape it into a statue of Elvis. Surely there is just one material object occupying the clay-filled space: a statue which is also a lump of clay. But surely the statue is something that only just came into existence, whereas the lump of clay has been in existence for a long time. So the statue and the lump of clay must be two different things, even though they occupy exactly the same space.

As we think about the various ways in which one might resolve paradoxes like this one, many other metaphysical questions will come up. We will embrace these opportunities for digression. As a result, by the end of the course, we will have considered a fair sampling of the traditional topics of metaphysics. These topics might include: questions about the existence and mind-independence of material objects; the nature of space and time; the possibility of time travel; the meaning of claims about possibility, necessity, and essence; the theory of composition; the existence and nature of properties and relations; the meaning of claims about causation and physical law; the freedom of the will; the criteria for, and significance of, personal identity.


Course Code: V83.0078-001

Instructor: Cian Dorr, 503H Main Building, office hours: Mondays at 3:00 PM or by appointment, email:

TA: Brad Skow, 503M Main Building, office hours: Wednesdays at 3.00 PM or by appointment, email:

Lecture Times: 11 - 12.15, Mondays and Wednesdays, Tisch LC4.

Who should take this course?

As indicated in the CAS Bulletin, this course is intended for students who have had some previous experience in philosophy. It will be presupposed that you already have some of the basic skills involved in analysing, evaluating and producing philosophical arguments. If you have never taken a philosophy class before, you might well find that things are going at too fast a pace, and that too much is being taken for granted. You should think seriously, while there is still time, about the possibility of switching into a more introductory philosophy course.


It is of essential importance that you should attend the lectures. A lot of important material that isn't discussed in the readings will be presented in the lectures. It is also important that you should on most occasions have done the required readings prior to the lecture for which they are assigned.

Instead of exams, there will be weekly problem sets and a final paper. A problem set will be handed out each Wednesday and due in class on the following Monday. 12 problem sets will be handed out in all; you must do 10 of them. No late problem sets will be accepted. You are encouraged to discuss the problem sets with fellow students; this is in fact a very good way to learn. However, if you do work with others, you must note this clearly, and you must put everything in your own words. The final paper will be due on May the 4th. It should be between 6 and 10 pages in length.


Your final grade will be determined as follows:

60% 10 weekly problem sets.
40% Final paper.


There are no compulsory textbooks for this course. A course packet containing those readings marked '(CP)' will be available from the University Copy Center on Waverly Place. The remaining readings will be distributed in class. Copies of the papers that are handed out will also be kept in a folder in the blue filing cabinet in the Philosophy Department library.


This is an extremely tentative syllabus that will certainly change considerably as the course goes on. Check this page frequently to keep up to date!

Every now and then, we will spend a session digressing from the main line of argument about the paradoxes of material consitution in order to discuss some other metaphysical question. These lectures have not been noted on the initial syllabus, since their timing and content will be heavily dependent on the speed with which we get through the basic material and on peoples' interests.
Date Topic and readings Handouts

Jan 16


Handout 1

Jan 22

Arguments and Paradoxes

Handout 2

Problem Set 1

Jan 24

The Paradoxes of Material Constitution (temporal versions)

Handout 3

Jan 29

Two Responses

Peter van Inwagen, 'The Doctrine of Arbitrary Undetached Parts' (sections 1-6)

Handout 4

Problem Set 2

Jan 31

David Wiggins, 'On Being in the Same Place at the Same Time'

Handout 5

Feb 5

Problem Set 3

Comments on P.S. 1

Feb 7


Handout 6

Feb 12

Temporal Parts

Ted Sider, Four-Dimensionalism, sections 1, 3.1, 3.2, 3.3.

Handout 7

Comments on P.S. 2

Feb 14

Time Travel

David Lewis, 'The Paradoxes of Time Travel' (CP)

Optional: Robert Heinlein, '—All You Zombies—'

Handout 8

Problem Set 4

Feb 21

Comments on P.S. 3

Feb 26

Arguments for Temporal Parts

David Lewis, Postscript B to 'Survival and Identity' (CP)

Sider, Four-Dimensionalism, section 4.5.

Handout 9

Handout 10

Comments on P.S. 4

Feb 28

Lewis, On the Plurality of Worlds, pp. 202-204 (CP)

Sider, Four-Dimensionalism, sections 4.6, 4.7.

Handout 11

Problem Set 5

March 5

Arguments Against Temporal Parts

Judith Jarvis Thomson, 'Parthood and Identity Across Time' (CP)

Handout 12

March 7

Eternalism and Presentism

Arthur Prior, 'Changes in Events and Changes in Things'

Handout 13

Problem Set 6

March 19

Personal Identity

Handout 14

Comments on P.S. 5

March 21

Bernard Williams, 'The Self and the Future' (CP)

Problem Set 7

March 26

Derek Parfit, 'Personal Identity'

Handout 15

March 28

David Lewis, 'Survival as Identity' (CP)

Handout 16

Problem Set 8

April 2

The Special Composition Question

Peter van Inwagen, Material Beings, up to p. 74 (CP)

Handout 17

April 4

Van Inwagen against Universalism

Peter van Inwagen, Material Beings, sections 8 and 9 (CP)

Handout 18

Problem Set 9

Comments on P.S. 7

April 9

More on composition

Peter van Inwagen, Material Beings, sections 10-13 (CP)

Handout 19

Final Paper Topics

April 11

Composition as a Fiction

Cian Dorr and Gideon Rosen, 'Composition as a Fiction'

Problem Set 10

Comments on P.S. 8

April 16

Modal versions of the paradoxes

Peter van Inwagen, 'The Doctrine of Arbitrary Undetached Parts' (section 7)

Handout 20

April 18

Ontological inflation

Kit Fine, 'Acts, Events and Things'

Handout 21

Problem Set 11

Comments on P.S. 9

April 23

Modal Realism

David Lewis, On the Plurality of Worlds, excerpts (CP)

Handout 22

April 25

Equivocation and the Paradoxes

David Lewis, On the Plurality of Worlds, excerpts (CP)

Optional: Sider, Four-Dimensionalism, section 5.8

Handout 23

Comments on P.S. 10

April 30

Concluding Remarks: Objectivity and Metaphysics

Handout 24


For the moment, I'll just include links to three excellent pages maintained by Jim Pryor: a glossary of philosophical terms and methods, a set of guidelines on writing philosophy papers, and a set of guidelines on reading philosophy papers.