Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter February 1, 2014

Sider’s Third Realm

  • Jonah P. B. Goldwater EMAIL logo
From the journal Metaphysica


Sider (2011; Writing the Book of the World. Oxford: Oxford University Press) argues it is not only predicates that carve reality at its joints, but expressions of any logical or grammatical category – including quantifiers, operators, and sentential connectives. Even so, he denies these expressions pick out entities in the world; instead, they only represent the world’s “structure”. I argue that this distinction is not viable, and that Sider’s ambitious programme requires an exotic ontology – and even a Fregean “third realm” – of logical entities.


Thanks especially to Barbara Montero, Tommy Kivatinos, and an anonymous referee for many helpful suggestions. Thanks also to the participants in Jonathan Schaffer’s Advanced Metaphysics Seminar at Rutgers University, March 2012.


Armstrong, D. 2004. Truth and Truthmakers. Cambridge: Cambridge University Press.10.1017/CBO9780511487552Search in Google Scholar

Ayer, A. J. 1936. Language, Truth, and Logic, 2nd edn. London: Victor Gollancz Ltd.Search in Google Scholar

Cameron, R. 2008. “Truthmakers and Ontological Commitment: Or How to Deal with Complex Objects and Mathematical Ontology Without Getting Into Trouble.” Philosophical Studies140:118.10.1007/s11098-008-9223-3Search in Google Scholar

Candlish, S. 2007. The Russell/Bradley Dispute and Its Significance for Twentieth-Century Philosophy. Palgrave Macmillan.10.1057/9780230800618Search in Google Scholar

Frege, G.. 1893. Grundgesetze Der Arithmetik, Vol. 1. Reprinted in Beaney, M. (ed.) (1997). The Frege Reader. Oxford: Blackwell Publishing.Search in Google Scholar

Frege, G.. 1918. Thought, 32545. Oxford: Reprinted in Beaney, M. (ed.) (1997).Search in Google Scholar

Lewis, D.. 1983. New Work for a Theory of Universals. Reprinted in Lewis, D. (1999). Papers in Metaphysics and Epistemology. Cambridge: Cambridge University Press.10.1017/CBO9780511625343Search in Google Scholar

Marek, J.. 2013. Alexius Meinong. The Stanford Encyclopedia of Philosophy (Fall 2013 Edition), Edward N.Zalta (ed.). in Google Scholar

Quine, W. V. O. 1948. “On What There Is.” Review of Metaphysics2(5):2136. Reprinted in (1953). From A Logical Point of View, 1–15. Harvard University Press.Search in Google Scholar

Quine, W. V. O. 1951. “Ontology and Ideology.” Philosophical Studies2:1115.10.1007/BF02198233Search in Google Scholar

Reicher, M. 2012. Nonexistent Objects. The Stanford Encyclopedia of Philosophy (Winter 2012 Edition), Edward N.Zalta (ed.). in Google Scholar

Russell, B. 1903. The Principles of Mathematics. London: W.W. Norton.Search in Google Scholar

Russell, B. 1905. “On Denoting.” Mind14:47993.10.1093/mind/XIV.4.479Search in Google Scholar

Russell, B. 1918. The Philosophy of Logical Atomism. Peru, Illinois: Open Court Publishing (1985).Search in Google Scholar

Russell, B. 1919. Introduction to Mathematical Philosophy. London: Routledge.Search in Google Scholar

Schaffer, J. 2008. “Truthmaker Commitments.” Philosophical Studies141:719.10.1007/s11098-008-9260-ySearch in Google Scholar

Sider, T. 2011. Writing the Book of the World. Oxford: Oxford University Press.10.1093/acprof:oso/9780199697908.001.0001Search in Google Scholar

Wittgenstein, L. 1921. Tractatus Logico-Philosophicus. Translated by D. F.Pears and B. F.McGuiness. London: Routledge and Kegan Paul (1961).Search in Google Scholar

  1. 1

    See e.g. Marek (2013) and Reicher (2012) for more detailed overviews of Meinong’s position.

  2. 2

    As parenthetically indicated, a Meinongian might distinguish ontological from “subsistential” commitment, i.e. between commitment to existence as opposed to being. For now, though, I’ll use “ontological commitment” to indicate commitment to any kind of reality whatever.

  3. 3

    Thus, certain traditional debates – such as nominalism vs realism about universals – can be recast in linguistic or quasi-linguistic terms: e.g. do predicate terms refer, as substantive terms do? Are predicates names for universals? (Of course, Quine answers in the negative.)

  4. 4

    Examples of this sort of talk abound. For instance, Sider writes that “In the case of logic… it’s plausible to think that there are joints in nature” (p. 222, original emphasis).

  5. 5

    This is so even on Sider’s own terms. For Sider claims that meta-metaphysics is “just more metaphysics” (p. 82), and, moreover, that “S(S)” is true – that is, that structure is itself structural (p. 137). And surely a dispute over this claim is a dispute as to whether there is structure.

  6. 6

    I take this to comport with the anti-Quinean doctrine of “truthmaker commitments”: roughly, that one is ontologically committed to every entity needed to make a sentence true, not only what it quantifies over. See Armstrong (2004), Cameron (2008), and Schaffer (2008) for criticism.

  7. 7

    More generally, Sider defends “purity” – the doctrine that fundamental facts are not contaminated by anything nonfundamental (see esp. §§7.2–7.3).

  8. 8

    Frege (1893, xvii), translated by, and reprinted in, Beaney (1997, 204–05).

  9. 9

    See Frege (1918) for his more robust defence of the third realm.

  10. 10

    Moreover, in this case “Pegasus does not exist” would be false – for if “Pegasus” means the subjective idea of Pegasus, and that idea exists (whenever it is thought), then Pegasus does indeed exist – contra the original statement.

  11. 11

    This is not to say, however, that they would be false: as these propositions would not be at all, they could not have (or bear) any truth-value whatever.

  12. 12

    Though Sider also accepts sets (ibid); whether this is already Platonism I leave for another day.

  13. 13

    See Plato’s Phaedrus, 265d–6a.

Published Online: 2014-2-1
Published in Print: 2014-4-1

©2014 by Walter de Gruyter Berlin / Boston

Downloaded on 24.9.2023 from
Scroll to top button