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Monism, Spacetime, and Aristotelian Substances


Schaffer offers us in the last section of “On What Grounds What” (2009) an applied illustration of his allegedly Aristotelian metaontological position. According to this illustration, Schaffer’s metaontological position, supplemented with a few Aristotelian theses about substance and grounding, would converge in a view remarkably similar to his priority monism (Philosophical Studies, 145, 131–148, 2009b; Philosophical Review, 119, 31–76, 2010a), the view that there is one single fundamental substance. In this paper, I will argue against Schaffer’s suggestion that priority monism represents a viable development of Aristotelian metaphysics. In particular, I will hold that the most plausible version of Schaffer’s priority monism by Aristotelian standards fails to satisfy basic Aristotelian tenets about dependence, composition, change, and persistence, and suggest that this is evidence that Aristotelians are more at home with a pluralism rather than a monism about substance.

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  1. 1.

    A further distinction that might be convenient to bear in mind when it comes to grounding is whether grounding is a unitary notion or rather captures a number of dependence relations that get to be designated by this broader notion. Given that subsequent discussion in Section 4 will be couched in terms of different notions of dependence, I will simply flag this issue here and move on (though see footnote 2 for further background on Schaffer’s stance on the matter).

  2. 2.

    I agree with both Steinberg (2015) and Calosi (2020) that Schaffer’s understanding of the notion of grounding is a sui generis one. Firstly, he equates the grounding relation described above with dependence, leaving us with one notion of fundamentality. As a consequence of that, he somehow transfers the category neutrality that is often associated with the notion of dependence to the grounding relation. However, as Calosi has argued (2020), there are important reasons why a priority monist such as Schaffer might want to keep them apart. When I come back in Section 4 to some of these issues, I will regiment the discussion for the sake of clarity in terms of different notions of dependence.

  3. 3.

    Here and in the following quotes from Aristotle, I follow Barnes’s translation (1984) with some occasional modifications of my own.

  4. 4.

    See also Metaph. 1019a2–4.

  5. 5.

    One should not assume here that Schaffer is denying one or some of the core axioms of CEM, such as Extensionality, but rather the metaphysically more robust thesis of Composition as Identity. In fact, Schaffer elsewhere explicitly does so (2010a, p. 38), at least as the view is formulated by Baxter (1988a, b). Moreover, Schaffer embraces elsewhere (2009b, p. 135; 2010a, p. 34) unrestricted composition, the mereological principle according to which for any plurality of things, there is a fusion of them. Unrestricted composition is instrumental to establishing the existence of the cosmos as a maximal concrete object, a central tenet of Schaffer’s monistic view. Also, unrestricted composition for material objects follows from supersubstantivalism—which Schaffer endorses (2009b)—and unrestricted composition for spacetime regions. That would certainly be a strange view to uphold if he were not also committed to extensionality. And lastly, it might just be, as an anonymous referee pointed out to me, that while still upholding CEM, Schaffer does not believe that it could provide us with a satisfactory account of integrated wholes.

  6. 6.

    Interestingly, Schaffer claims that this set of definition has the correct result that if the universe is an integrated whole, then all its proper parts would turn out interdependent.

  7. 7.

    Notice that on the version I introduce here of this dependence relation not only do we exclude cases where such relation might hold symmetrically between two objects (think, for instance, on the typical Socrates and singleton Socrates Fine cases), but also any case in which we might want to say an object depends on itself.

  8. 8.

    Lowe expands his initial criticism in more than two directions (2012). He claims that Schaffer’s priority monism controversially assumes universalism and that Schaffer’s notion of the cosmos is simply too vague to be the proper object of study of any scientific discipline. However, I shall not be concerned with these objections here, but rather discuss in length the two objections presented in this section.

  9. 9.

    For Schaffer’s own proposal, see Schaffer (2009b).

  10. 10.

    I am assuming that the location relation referred to here is the exact location relation developed by Varzi and Casati (1999), Gilmore (2006, 2007), and McDaniel (2007), though following Gilmore and McDaniel in not assuming that exact location entails functionality, the principle that an object cannot have more than one exact location. A further caveat regarding the reflexivity of exact location is also required. Our location relation is a relation that either relates objects to regions or regions to regions, but not objects to objects. Assuming that, to claim that exact location is a reflexive relation cannot imply that every object is exactly located at itself. Rather, it implies only that every region is located at itself. Given that in Schafer’s view objects are identical to the regions that contained, our location relation will be a relation that connects regions to regions.

  11. 11.

    See Fine Lowe (1998), Fine (2003, 2006), and Koslicki (2008) for some contemporary examples.

  12. 12.

    See again Fine (1994, 2008, 2010), Johnston (2006), Koslicki (2008, 2013), Brower (2010), and Jaworski (2016) for a few notorious recent examples. One particularly useful place within Aristotle’s corpus to find an attempt where this distinction ifs fleshed out in detail is Metaph. Z 7-9. In Metaph. Z 8, for instance, Aristotle claims the following:

    It is obvious then from what has been said that the thing, in the sense of form or substance, is not produced, but the concrete thing which gets its name from this is produced, and that in everything which comes to be matter is present, and one part of the thing is matter and the other form. (Metaph. 1033b17-9)

  13. 13.

    See specifically Fine (2008), Koslicki (2008), and Sattig (2015).

  14. 14.

    See also Physics 190a32-37) for another passage where Aristotle makes this specific point and, more generally, Physics A 6-7.

  15. 15.

    Though see Wedin (2000, pp. 300-314) for an attempt in that direction.

  16. 16.

    The generic existential dependence relation that I am introducing here from Thako and Lowe (2020) is not strictly necessary for the argument I pursue in the rest of the section, which in fact only requires the following modal version of this relation:

    x depends for its existence upon Fs =df Necessarily, x exists only if some F exist.

    I stick nonetheless to its more fine-grained essentialist version to somehow mirror the essentialist identity dependence relation introduced before.

  17. 17.

    It is interesting to notice that Aristotle seems to even go beyond what he claims Metaph. 1036a14-25 in De Partibus Animalium 670a23-27, where he suggests that there is a hierarchy in the dependence between the constituents of a living organism and the organism itself. Thus, it turns out, according to Aristotle, that we might regard the heart and the liver as essential constituents of animals over, let us say, a leg, an ear, or even an eye.

  18. 18.

    Calosi (2020) offers a reply to this counter-example on behalf of priority monism. Steinberg claims that the example above entails the principle of isolated duplicates, according to which:

    For any composite object o—with parts p1; . . .; pn—that exists at @, there is a possible world w such that the only concrete objects that exist at w are o’s duplicate, o*, and the duplicates of o’s parts, p*1; . . .; p*n. (2015, p. 2029).

    However, Calosi rightly points out that it is not obvious why priority monists should accept such principle. The best reason to my mind offered by Calosi is that the Principle of Isolated Duplicates is a principle that is part and parcel with Humean metaphysical frameworks that allow for free recombinability. But priority monists (and also Aristotelians) have principled reasons to reject free modal recombination. Of course, this is not a conclusive argument to discard the Principle of Isolated Duplicates, which seems to have an appeal regardless of its Humean ties—but it certainly puts the weight of Steinberg’s objection into perspective.


  1. Audi, P. (2012). A clarification and defense of the notion of grounding, in Correia and Schnieder 2012, pp. 101-21.

  2. Barnes, J. (1984). The complete works of Aristotle. Princeton: Princeton University Press.

    Google Scholar 

  3. Baxter, D. (1988). Identity in the loose popular sense. Mind, 97, 575–582.

    Article  Google Scholar 

  4. Baxter, D. (1988a). Many-one identity. Philosophical Papers, 17, 193–216.

    Article  Google Scholar 

  5. Bliss, K., Torgdon, K. (2014). Metaphysical grounding, in Stanford encyclopaedia for philosophy, accessed last time on 27/11/17 (

  6. Brower, J. (2010). Aristotelian endurantism: A new solution to the problem of temporary intrinsics. Mind, 119, 883–905.

    Article  Google Scholar 

  7. Calosi, C. (2020). Priority monism, dependence, and fundamentality. Philosophical Studies, 177(1), 1–20.

    Article  Google Scholar 

  8. Chalmers, D. J., et al. (Eds.). (2009). Metametaphysics: New essays on the foundations of ontology. Oxford: Oxford University Press.

    Google Scholar 

  9. Correia, F. (2010). Grounding and truth-functions. Logique et Analyse, 53, 251–279.

    Google Scholar 

  10. Correia, F., & Schnieder, B. (2012). Metaphysical grounding: Understanding the structure of reality. Cambridge: Cambridge University Press.

  11. Feser, E. (Ed.). (2013). Aristotle on Method and Metaphysics. Basingstoke: Palgrave/Macmillan.

  12. Fine, K. (2012). A guide to ground. In Correia y Schnieder 2012, pp. 37-80.

  13. Fine, K. (2010). Towards a theory of part. Journal of Philosophy, 107, 559–589.

    Article  Google Scholar 

  14. Fine, K. (2008). In defence of three-dimensionalism. Philosophy, 83, 1–16.

    Article  Google Scholar 

  15. Fine, K. (2006). Arguing for non-identity: A response to King and Frances. Mind, 115(460), 1059–1082.

    Article  Google Scholar 

  16. Fine, K. (2003). The non-identity of a material thing and its matter. Mind, 112, 195–234.

    Article  Google Scholar 

  17. Fine, K. (1994). Compounds and aggregates. Noūs, 28, 135–158.

    Google Scholar 

  18. Gilmore, C. (2007). Time-travel, coinciding objects, and persistence. In Zimmerman 2007, pp. 177-98.

  19. Gilmore, C. (2006). Where in the relativistic world are we? Philosophical Perspectives, 20, 199–236.

    Article  Google Scholar 

  20. Goff, P. (2012). Spinoza on Monism. Basingstoke: Palgrave MacMillan.

    Google Scholar 

  21. Hale, B., & Hoffmann, A. (Eds.). (2010). Modality: Metaphysics, logic, and epistemology. Oxford University Press.

  22. Jaworski, W. (2016). Structure and the metaphysics of mind. Oxford: Oxford University Press.

    Book  Google Scholar 

  23. Johnston, M. (2006). Hylomorphism. Journal of Philosophy, 103, 652–698.

    Article  Google Scholar 

  24. Koslicki, K. (2008). The structure of objects. Oxford: Oxford University Press.

    Book  Google Scholar 

  25. Koslicki, K. (2013). Substance, Independence, and Unity. In Feser, 169–195.

  26. Lowe, J. (2012). Against monism. In Goff, 2012, 92–112.

    Google Scholar 

  27. Lowe, J. (1998). The possibility of metaphysics. Oxford: Oxford University Press.

    Google Scholar 

  28. McDaniel, K. (2007). Extended simples. Philosophical Studies, 133, 131–141.

    Article  Google Scholar 

  29. Quine, W. V. O. (1953). From a logical point of view. Cambridge, MA: Harvard University Press.

    Google Scholar 

  30. Quine, W. V. O. (1953a). On what there is. In Quine, 1953, 1–19.

    Google Scholar 

  31. Quine, W. V. O. (1953b). Logic and the reification of universals. In Quine, 1953, 102–129.

    Google Scholar 

  32. Rosen, G. (2010). Metaphysical dependence: Grounding and reduction. In Hale and Aviv Hoffmann, 2010, 109–136.

    Google Scholar 

  33. Sattig, T. (2015). The double lives of objects. Oxford: Oxford University Press.

    Book  Google Scholar 

  34. Schaffer, J. (2013). The action of the whole. Proceedings of the Aristotelian Society, Supplementary Volumes, 87, 67–87.

    Article  Google Scholar 

  35. Schaffer, J. (2010a). Monism: the priority of the whole. Philosophical Review, 119, 31–76.

    Article  Google Scholar 

  36. Schaffer, J. (2010b). The least discerning and most promiscuous truthmaker. The Philosophical Quarterly, 60, 307–324.

    Article  Google Scholar 

  37. Schaffer, J. (2009a). On what grounds what. In Chalmers et al., 2009, 347–383.

    Google Scholar 

  38. Schaffer, J. (2009b). Spacetime the one substance. Philosophical Studies, 145, 131–148.

    Article  Google Scholar 

  39. Schnieder, B. (2020). Grounding and dependence. Synthese, 197(1), 95–124.

    Article  Google Scholar 

  40. Steinberg, A. (2015). Priority monism and part/whole dependence. Philosophical Studies, 172, 2025–2031.

    Article  Google Scholar 

  41. Tallant, J. (2015). Ontological dependence in a spacetime world. Philosophical Studies, 172, 3101–3118.

  42. Thako, T., & Lowe, J. (2020). Ontological dependence, in Stanford encyclopaedia for philosophy  Accessed 13 Mar 2021

  43. Varzi, A., & Casati, R. (1999). Parts and places. Cambridge: Bradford Books.

    Google Scholar 

  44. Wedin, M. (2000). Aristotle’s theory of substance: The categories and metaphysics zeta. Oxford: Oxford University Press.

    Google Scholar 

  45. Zimmerman, D. (Ed.). (2007). Oxford studies in metaphysics, Volume 3. Oxford: Oxford University Press.

    Google Scholar 

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Rossi, C. Monism, Spacetime, and Aristotelian Substances. Acta Anal 36, 375–392 (2021).

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  • Aristotle
  • Substance
  • Priority monism
  • Dependence
  • Spacetime