Philosophy 401 - Undergraduate Seminar on Ontology

  • Thursdays, 4:00-6:45P, Hall of Languages 201
  • Ted Sider, HL 537, xt. 5817,
  • Office Hours: Wednesday, Thursday, 2:00-3:00


This will be a seminar on ontology, specifically, the ontology of material objects in time and space. We'll start with some questions about composite objects. Apparently, some objects have others as parts; for example, a lot of electrons are part of me. Objects like me we call "composite". The philosophical question here is: what composite objects exist? Do there exist "scattered" composite objects, like decks of cards? Do we accept the existence of a composite object whenever some parts exist, or only when the parts are suitably arranged or stuck together? Why think there are any composite things at all?

We'll then turn to some topics in the philosophy of time. Philosophers have had all sorts of interesting things to say about time. One of the most interesting (and bizarre) is that there really is no such thing as time. J. M. E. McTaggart thought that the concept of time is incoherent and therefore there really is no such thing as time. The core of his reason for thinking that time is incoherent centers on the notion of time's "passage" or "flow". We all think that time flows, but it can make you dizzy if you stop to think about this a bit; what is time flowing past, and how fast is it flowing? Many agree with McTaggart that time doesn't flow, but stop short of denying the existence of time altogether. They think that time is a lot like space: a fourth dimension in which objects are located, but which does not "move". Still others think that McTaggart was completely wrong, and that time really does flow. A related question philosophers ask is whether it is logically possible to travel back in time. Some think not, because if time travel were possible then someone could travel back in time and kill her grandfather, thus preventing herself from existing in the first place!

Finally we'll turn to a topic that combines concerns from the first two: persistence over time. We all believe that some things last, or persist over time. Persons, for example, surely last over time, for otherwise it would be unfair to punish people for crimes committed in the past -- no one is guilty of a crime committed by someone else! But persistence over time raises many issues. How can persons continue to exist over time when they change? Persons, in fact, change all their constituent matter over time. Another puzzle: suppose we take a statue and smash it. We seem to have destroyed the statue, but not the lump of clay. So that means that the statue and the lump of clay were two different things (since only one is vulnerable to destruction by smashing). But now we seem to be admitting that it is possible to have two things in the very same place at the same time!


  • Three short papers (2-4 pages), worth 15% of the grade each, due 9/20, 10/25, and 12/6. Topics TBA.
  • One final paper (8-15 pages), worth 45% of the grade, due 12/19. I am willing to comment on rough drafts; if you want me to do this then you should get me the rough draft by a reasonable time before the paper is due.
  • Participation, worth 10%. This includes class attendance and participation, as well as email contact with me (in case you're shy).


  • Readings, optional and required. The readings for each week are listed on the schedule below. Be sure to do the reading before each meeting -- since this is a seminar I will be expecting a lot out of you in class discussion. The readings are difficult, so you will need to read carefully and thoroughly. If you have questions about the week's reading, feel free to email them to me. All readings are required unless designated "OPTIONAL".
  • Books
    • Peter van Inwagen, Material Beings. This is a bit expensive ($50); if this is a problem for anyone, let me know. I have ordered it at Folletts Orange Bookstore on Marshall St.
    • Ted Sider, Four-Dimensionalism: An Ontology of Persistence and Time. This isn't available yet; it should be available in early October. I will let you know details then.
    • Here are a couple of anthologies you might be interested in purchasing. Neither is mandatory; the readings from each will be on reserve in the library. Each is available on the web at various bookstores.
    • Robin Le Poidevin and Murray MacBeath, eds., The Philosophy of Time (Oxford University Press, 1993)
    • Michael Rea, ed., Material Constitution: A Reader (Rowman & Littlefield, 1997).
  • Articles on reserve. All readings other than those in the required books will be placed on reserve in Bird Library.

Tentative schedule

Week 1 (8/30): Introductory stuff on ontology, van Inwagen on composites.

  • Material Beings chapters 1-3

Week 2 (9/6): Van Inwagen on composites (continued)

  • Material Beings chapters 6-8

Week 3 (9/13): Van Inwagen on composites continued

  • Material Beings chapters 9-12

Week 4 (9/20): McTaggart and the B-theory of time **Short paper #1 due**

  • McTaggart, "Time: an Excerpt from The Nature of Existence"
  • Smart, "The Space-Time World"
  • OPTIONAL: "Time without Change", "The Myth of Passage", "Spatial and Temporal Analogies and the Concept of Identity"

9/27, Yom Kippur, no class

Week 5 (10/4): The A-theory and presentism

  • Broad, excerpt from Examination of McTaggart's Philosophy
  • Markosian, "How Fast Does Time Pass?"
  • Prior, "The Notion of the Present"
  • Prior, "Thank Goodness That's Over"

Week 6 (10/11): More presentism

  • Bigelow, "Presentism and Properties"
  • OPTIONAL: Sider, Four-Dimensionalism chapter 2

Week 7 (10/18): Time travel

  • Lewis, "The Paradoxes of Time Travel"
  • Sider, "Time Travel, Coincidences and Counterfactuals"

Week 8 (10/25): Intro to persistence, four-dimensionalism **Short paper #2 due**

  • Sider, Four-Dimensionalism chapter 1; chapter 4 sections 1-3, 5
  • OPTIONAL: Sider Four-Dimensionalism chapter 3; chapter 4 section 4

Week 9 (11/1): Arguments for four-dimensionalism

  • Lewis, "The Problem of Temporary Intrinsics"
  • Sider, Four-Dimensionalism chapter 4, sections 6-9

Week 10 (11/8): The paradoxes of coincidence: moderate 3D views

  • Wiggins, "On Being in the Same Place at the Same Time"
  • Sider, Four-Dimensionalism chapter 5, sections 1-4
  • OPTIONAL: Burke, "Preserving the Principle of One Object to a Place: A Novel Account of the Relations among Objects, Sorts, Sortals, and Persistence Conditions"

Week 11 (11/15): The paradoxes of coincidence: extreme 3D views

  • van Inwagen, "The Doctrine of Arbitrary Undetached Parts"
  • Sider, Four-Dimensionalism chapter 5, sections 6-7

Week 12 (11/29): The paradoxes of coincidence: the stage view

  • Sider, Four-Dimensionalism chapter 5, section 8

Week 13 (12/6): Problems for four-dimensionalism ** Short paper #3 due **

  • Sider, Four-Dimensionalism chapter 6