Worldmates and internal relatedness


In recent work, Jonathan Schaffer (Mind 119: 341–376, 2010) has attempted to argue that counterpart theorists are committed to holding that any two actual objects are bound together in a modally substantial sense. By clarifying the core elements of counterpart theory, I explain why Schaffer’s argument fails.

This is a preview of subscription content, access via your institution.


  1. 1.

    Strictly speaking, the claim is weaker than this. All that is required is that for each pair of objects 〈x,y〉 there is some internal relation which holds between x and y. And that doesn’t require that there is a single internal relation R by which everything is related.

  2. 2.

    I assume here that Billy can’t have properties at worlds where he doesn’t exist, so that Billy’s how-possibilities can’t be combined with the whether-possibility of not existing.

  3. 3.

    That’s not quite right, of course, since we need to rule out combination pairs where x and y are co-located. See Schaffer (2010, pp. 13, 14) for discussion.

  4. 4.

    This definition only covers the binary case, but it generalizes in an obvious way.

  5. 5.

    It’s worth noting that Lewis means that nothing is wholly located in more than one world. Lewis does believe in the existence of fusions of things from different worlds, and these things are partially in many worlds.

  6. 6.

    To be clear: I’m not suggesting that these strange and unfamiliar notions of similarity play a role in Schaffer’s argument. The point is rather that the counterpart theorist insists that de re modal claims—such as claims about modal freedom—must be negotiated by appeal to counterparts and thereby similarity relations. So Schaffer cannot conclude that the counterpart theorist is committed to a given de re modal claim without making some assumptions about which similarity relations are contextually salient. And as far as I can tell, Schaffer’s conclusion only follows in some quite bizarre contexts. Thanks to an anonymous referee for forcing me to be clear on this.


  1. Lewis, D. (1968). Counterpart theory and quantified modal logic. Journal of Philosophy, 65, 26–113.

    Article  Google Scholar 

  2. Lewis, D. (1986). On the plurality of worlds. Oxford: Basil Blackwell.

    Google Scholar 

  3. Plantinga, A. (1974). The nature of necessity. Oxford: Oxford University Press.

    Google Scholar 

  4. Schaffer, J. (2010). The internal relatedness of all things. Mind, 119, 341–376.

    Article  Google Scholar 

Download references


With thanks to Ross Cameron and Tatjana von Solodkoff. My research on this paper was partially supported by my involvement in the Nature of Assertion: Consequences for Relativism and Fictionalism project (FFI2010-169049), the Vagueness and Physics, Metaphysics, and MetaMetaphysics project (FFI2008-06153), and the Persp-Philosophy of Perspectival Thoughts and Facts project (CSD2009-00056). Many thanks to the DGI, MICINN, and the Spanish Government for supporting these projects.

Author information



Corresponding author

Correspondence to Richard Woodward.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Woodward, R. Worldmates and internal relatedness. Philos Stud 166, 419–427 (2013).

Download citation


  • Actual World
  • Concrete Object
  • Logical Space
  • Modal Language
  • Modal Profile