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Solitude without Souls: Why Peter Unger hasn’t Established Substance Dualism


Unger has recently argued that if you are the only thinking and experiencing subject in your chair, then you are not a material object. This leads Unger to endorse a version of Substance Dualism according to which we are immaterial souls. This paper argues that this is an overreaction. We argue that the specifically Dualist elements of Unger’s view play no role in his response to the problem; only the view’s structure is required, and that is available to Unger’s opponents. We outline one such non-Dualist view, suggest how to resolve the dispute, respond to some objections, and argue that ours is but one of many views that survive Unger’s challenge. All these views are incompatible with microphysicalism. So Unger’s discussion does contain an insight: if you are the only conscious subject in your chair, then microphsyicalism is false. Unger’s mistake was to infer Substance Dualism from this; for microphysicalism is not the only alternative to Dualism.

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  1. On another usage, Materialism is the view that mental properties are, in some sense, non-fundamental. This is not our usage. Our usage contrasts with Substance Dualism, which concerns the bearers of mental properties. However, dualism about objects presumably implies dualism about properties; for how could an immaterial object’s properties all be grounded in material properties?

  2. Throughout, all page references without dates are to Unger (2006).

  3. Unger’s argument comprises more than one-hundred pages of his six-hundred-and-forty page (2006).

  4. Strictly, the Substance Dualist also denies Uniqueness: you are not in your chair, but an immaterial soul without spatial location. Let us use locational vocabulary in an extended sense so that a soul counts as located wherever its body is located.

  5. Wright (2010) contains a powerful recent expression of scepticism about higher-order vagueness, and references to earlier debate. Fara (2004) argues that higher-order vagueness cannot exhaust the phenomenon of seamless transition it was introduced to explain.

  6. We do not assume that C is non-disjunctive or intrinsic.

  7. If human bodies exist before or after their embodied subjects, then this will need finessing.

  8. We discuss an objection to the novelty of Experiencers in Digression: A little More on Experiencers.

  9. We mean the pre-philosophically understood notion of parthood, without commitment to any theory of parthood.

  10. So far, our view permits Experiencers to have some immaterial parts; Digression: A little More on Experiencers rules this out.

  11. Though see notes 10 and 13.

  12. One might worry that Mii rules out possibilities that should be left open, e.g.: our planet is a tiny cell in an unfathomably large thinker. If so, then we restrict our claims (including Mii) to subjects akin to ourselves.

  13. x fuses the ys iff each of the ys is part of x and x has no parts disjoint from each of the ys. Note that appeal to mereological concepts like fusion does not imply any particular theory of parthood. We can, and do, remain neutral about the temporal and modal invariance of fusion, and about whether fusion is unrestricted or unique. As note 10 promised, our proposal now implies that Experiencers have only material parts.

  14. Our proposal resembles the suggestion that humans constitute material persons which, unlike humans, have a conscious mental life (cf. Baker 2000). One difference, crucial to our strategy, is that parthood, unlike constitution, is usually regarded as one-many.

  15. Maybe H becomes the only human in your chair. Or maybe the humans previously in your chair all now coincide with H. It doesn’t matter for our purposes.

  16. Notable examples include: Wiggins (1968, 2001), Fine (2003).

  17. A full-blown defence of coincidence is beyond the scope of this paper. (Though see Digression: A little More on Experiencers) However, the key point here is that the explanatory tools we require are not novel.

  18. Two more examples. Minute increases in global temperature ground significant differences in global climate. Slightly too much complaining causes your patience to snap.

  19. Compare: the laws governing statues determine that atoms embedded within a statue are parts of it, and hence that anything that doesn’t include them isn’t a statue. It doesn’t follow that such atoms make any contribution to the statue’s aesthetic properties.

  20. van Inwagen (1990, ch.12) claims that this is impossible. It is, however, unclear whether van Inwagen argues for this claim, or simply assumes it.


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We would like to thank Dorothy Edgington, Chris Hughes, Fraser MacBride, Chris Machut and Peter Unger for comments and discussion. Will’s research was funded by a University of London Jacobsen Fellowship; Nick’s research was funded by an AHRC Doctoral Award, an RIP Jacobsen Fellowship, and a University of London Jacobsen Fellowship; we are grateful to all these organisations.

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Correspondence to Nicholas K. Jones.

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Bynoe, W., Jones, N.K. Solitude without Souls: Why Peter Unger hasn’t Established Substance Dualism. Philosophia 41, 109–125 (2013).

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  • Problem of the many
  • Constitution
  • Substance dualism