1 An earlier version of this paper was given at Monash University, and I thank members of the audience there — especially Dirk Baltzly, John Bigelow, and J.J.C. Smart — for useful feedback. This work developed from a paper that I gave at a conference on personal identity held at Bowling Green State University in April 2004. I thank my co-conferees there — especially Lynne Baker, Stephen Braude, David Copp, John Finnis, David Oderberg, and Marya Schechtman — for their critical feedback on the paper given there. Thanks also to Andrew Brennan, Dean Zimmerman, and Lynne Baker (again) for feedback on related work. And thanks to two referees for the CJP whose comments proved helpful in shaping up the final version, and to Jackie Ostrem and Bart Lenart for proofreading help. See also my ‘Persons, Social Agency, and Constitution,’ Social Philosophy and Policy 22 (2005) 49-69; ‘A Puzzle About Material Constitution and How to Solve It: Enriching Constitution Views in Metaphysics,’ Philosopher's Imprint 7(5) (2007) 1-20; and ‘The Transitivity of Material Constitution,’ Nous 43 (2009).

2 Well-known appeals to constitution, all focused on the case of persons, include those by Wiggins, David ‘On Being in the Same Place at the Same Time,’ Philosophical Review 77 (1968) 90-5;CrossRefGoogle Scholar Johnston, Mark ‘Constitution is Not Identity,’ Mind 101 (1992) 89–105;CrossRefGoogle Scholar and Shoemaker, Sydney ‘Self, Body, and Coincidence,’ Proceedings of the Aristotelian Society supp. 73 (1999) 287–306.CrossRefGoogle Scholar For a recent discussion of Shoemaker, see Dean Zimmerman, ‘Shoemaker's Metaphysics of Minds, Bodies, and Properties,’ Philosophy and Phenomenological Research in press.

3 For a sustained discussion of the standard objection to constitution views that in cases such as that of a person and her body we really have just one thing to which we attach different descriptions, see Fine, Kit ‘The Non-Identity of a Material Thing and Its Matter,’ Mind 112 (2003) 195–234;CrossRefGoogle Scholar Frances, Bryan ‘The New Leibniz Law Arguments for Pluralism,’ Mind 115 (2006) 1007-22;CrossRefGoogle Scholar King, Jeffrey ‘Semantics for Monists,’ Mind 115 (2006) 1023-58;CrossRefGoogle Scholar and Fine, Kit ‘Arguing for Non-Identity: A Response to King and Frances,’ Mind 115 (2006) 1059-82.CrossRefGoogle Scholar

4 The discussion of constitution views that comes perhaps closest to articulating this problem can be found in the work of Ernest Sosa, especially his ‘Subjects Among Other Things,’ Philosophical Perspectives 1 (1987) 155-87, where Sosa introduces the ‘snowdiscall problem.’ See also his ‘Putnam's Pragmatic Realism,’ Journal of Philosophy 90 (1993) 605-26, and ‘Existential Relativity,’ Midwest Studies in Philosophy 23 (1999) 132-43, as well as the related, more general discussions of Peter, Unger ‘The Problem of the Many,’ Midwest Studies in Philosophy 5 (1980) 411-67,Google Scholar and Hirsch, Eli Dividing Reality (New York: Oxford University Press 1993).Google Scholar One difference between my discussion of the Many-Many Problem and these related discussions is that they question the privileging of whole ontologies, including that provided by common sense, while the Many-Many Problem arises within our common sense ontology.

5 I borrow talk of ‘one-thing’ and ‘two-thing’ ontologies from Bennett, Karen ‘Spatio-Temporal Coincidence and the Grounding Problem,’ Philosophical Studies 118 (2004) 339-71,CrossRefGoogle Scholar who owes it, in turn, to Steve Yablo. See also the characterization of constitution views as a ‘new dualism’ in Michael Burke, ‘Persons and Bodies: How to Avoid the New Dualism,’ American Philosophical Quarterly 34 (1997) 457-67.

6 See Baker, Lynne Rudder Persons and Bodies: A Constitution View (New York: Cambridge University Press 2000);CrossRefGoogle Scholar ‘Why Constitution is Not Identity,’ Journal of Philosophy 94 (1997) 599-621; ‘Unity Without Identity: A New Look at Material Constitution,’ Midwest Studies in Philosophy 23 (1999) 144-65; ‘On Making Things Up: Constitution and its Critics,’ Philosophical Topics 30 (2002) 31-51; ‘Précis’ and ‘Replies’ in a book symposium in Philosophy and Phenomenological Research 64 (2002) 592-98 and 623-35; and ‘When Does a Person Begin?’ Social Philosophy and Policy 22 (2005) 25-48. For a sustained critique of Baker's view, see Dean Zimmerman, ‘The Constitution of Persons by Bodies: A Critique of Lynne Rudder Baker's Theory of Material Constitution,’ Philosophical Topics 31 (2002) 295-338; and for a recent account of constitution alternative to Baker's, see Ryan Wasserman, ‘The Constitution Question,’ Noûs 38 (2004) 693-710.

7 For mereological views, see, for example, Lewis, David K. Parts of Classes (Oxford: Blackwell 1991), esp. 81-7Google Scholar (where the discussion is cast in terms of ‘composition’); Zimmerman, Dean ‘Theories of Masses and Problems of Constitution,’ Philosophical Review 104 (1995) 53–110;CrossRefGoogle Scholar Rea, Michael ‘The Problem of Material Constitution,’ Philosophical Review 104 (1995) 525-52;CrossRefGoogle Scholar and Thomson, Judith ‘The Statue and the Clay,’ Noûs 32 (1998) 149-73.CrossRefGoogle Scholar For Baker's discussion of why she eschews mereology in her account of constitution, see Persons and Bodies, 179-85, but note the mereological element in her ‘Unity Without Identity: A New Look at Mereological Constitution.’ Whether foregoing a mereological element in the constitution view is a mistake is an issue beyond the scope of the current paper.

8 In ‘On Making Things Up: Constitution and its Critics,’ Baker characterizes constitution as a form of non-identity that is different from separate existence, in part to highlight the sense in which constitution is a unity-making relation. This is a shift in emphasis, rather than a substantive change in view, and what I say below should hold on either characterization.

9 The distinction between what I am calling ampliative and deflationary views of c onstitution is developed in my ‘A Puzzle About Material Constitution and How to Solve It: Enriching Constitution Views in Metaphysics.’

10 Persons and Bodies, 21

11 I follow Kit Fine, ‘The Non-Identity of a Thing and Its Matter,’ 197-8, in appealing to both spatial and material coincidence chiefly as a way of bypassing continuing disagreement (especially between Baker and her critics) about which of these should feature in an account of constitution. Baker's abandonment of mereology (see footnote 7 above) left her with only spatial coincidence in her own non-mereological view of constitution. But an appeal to material coincidence is compatible with eschewing mereology, provided that one avoids analyzing material coincidence in terms of the sharing of parts. A weaker notion of constitution that requires only spatial coincidence has counter-intuitive implications — such as a material object being constituted by the region of space it occupies, or ghosts that spatially coincide with a person for some period of time being constituted by that person — implications that do not hold of a stronger notion that requires material coincidence as well.

12 The controversy here stems largely from the common but mistaken view that both genes and persons are individuated entirely by their intrinsic properties. On many views of persons, and especially those appealed to within constitution views, persons are individuated in part by their mental states or mental capacities. Yet these in general are not intrinsic properties, for well-known externalist reasons. Genes, by contrast, are functional entities, where their function is not simply to code for proteins (although many do), but also to regulate the functioning of other genes in various ways (as promoters, enhancers, inhibitors, etc.). This characterization of genes implies that their existence conditions include facts about the world beyond the spatial boundary shared by particular genes and particular strands of DNA. For a development of this point in the context of a broader discussion of genetics and development, see my Genes and the Agents of Life (New York: Cambridge University Press 2005), chapters 6-7.

13 Although I view each of these formal properties as desirable, at one time or another all have been called into question as properties of constitution. For discussion of some of the complexities concerning the transitivity of constitution, see my ‘The Transitivity of Material Constitution.’

14 For an interesting, recent discussion of views that in effect deny distinctness because they deny that dead bodies exist at all, see Hershenov, David ‘Do Dead Bodies Pose a Problem for Biological Approaches to Personal Identity?’ Mind 114 (2005) 31–59.CrossRefGoogle Scholar

15 Whether Aristotle himself should be seen as accepting what I am calling ‘Aristotelian strengthening’ turns on complicated issues concerning not only how we should understand the distinction between form and matter, but also on the appropriateness of reading a constitution-based metaphysics into Aristotle's metaphysics at all. (Thanks to Dirk Baltzly for a comment that prompted this caveat.) For Aristotle's views on substances, see his Metaphysics, especially books VII (Z) and VIII (H), in Barnes, Jonathan ed., The Complete Works of Aristotle: The Revised Oxford Translation, Volume Two (Princeton, NJ: Princeton University Press 1984).Google Scholar

16 See, for example, Persons and Bodies, 39-46. Others (including Aristotle and Peter Strawson, in Individuals: An Essay in Descriptive Metaphysics [London: Methuen 1959]) have used the term ‘primary kinds,’ but such uses appear to be coincidental with Baker's usage. For a very brief discussion of how the constitution view compares to Aristotle's own views, see Baker's ‘On Making Things Up,’ footnote 4 and the paragraph it footnotes. For a recent exploration of ontologically privileged categories, see Westerhoff, Jan ‘The Construction of Ontological Categories,’ Australasian Journal of Philosophy 82 (2004) 595–620.CrossRefGoogle Scholar

17 The quotation is from Persons and Bodies, 41. See also Baker's discussion more generally in Chapter 2 of that book.

18 For animalism, see Olson, Eric The Human Animal: Personal Identity Without Psychology (New York: Oxford University Press 1997),Google Scholar and for four-dimensionalism, see Sider, Theodore Four-Dimensionalism: An Ontology of Persistence and Time (New York: Oxford University Press 2001). 11CrossRefGoogle Scholar