Abstract
It has often been thought that compositional variation across systems that are similar from the point of view of the special sciences provides a key point in favor of the multiple realization of special science kinds and in turn the broadly nonreductive consequences often thought to follow from multiple realization. Yet in a series of articles, and culminating in The Multiple Realization Book, Tom Polger and Larry Shapiro argue that an account of multiple realization demanding enough to yield such nonreductive consequences implies that compositional variation is far less significant for the multiple realization of special science kinds than many have supposed. I argue, in contrast, that even on this demanding account, lower-level compositional variation may frequently support the multiple realization of special science kinds across the systems of interest, and that there is a good explanation for where Polger and Shapiro go wrong in drawing the contrary conclusion. I consider but reject Carl Gillett’s claim that different views about the significance of compositional variation for multiple realization phenomena should be traced to implicit disagreement about the metaphysics of realization.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
See especially Boyd (1980) and Fodor (1974). While Putnam appears to deny that compositional variation always suffices for multiple realization—for example, he allows that the kind eye or property being an eye is uniformly realized across humans and octopuses, despite compositional differences in human and octopus eyes—he nonetheless emphasizes that a functionalist view of mind allows that differently composed systems may possess the same kind of mental states. For recent discussions that emphasize the significance of compositional variation for multiple realization, see Gillett (2003) and Aizawa and Gillett (2009a, b, 2011).
One issue that I will largely gloss over concerns the proper relata of multiple realization—just what it is that is multiply realized and does the multiple realizing. Polger and Shapiro officially define multiple realization for kinds—multiple realization, on Polger and Shapiro’s official account, involves sameness of kind according to one theory together with difference of kind in some other theory (2016, p. 67). However, they are on the whole ambivalent about the proper relata of multiple realization, and sometimes speak of properties, states, and processes as multiply realized (see, for example, 2016, p. 27); similarly, they allow that items from various ontological categories can stand in the realization relation (2016, pp. 22–3). They also present their account as a competitor to those that take properties to be multiply realized (as in Gillett (2003) and Aizawa and Gillett (2009a, b, 2011) but they do not reject the latter because they take properties rather than kinds as what is multiply realized. One might reasonably wish for Polger and Shapiro to be clearer, or more decisive, on these issues concerning the ontology of realization and multiple realization. In any case, I will proceed as follows. First, my own view is that most or all of what Polger and Shapiro say about compositional variation and multiple realization is insensitive to these issues and can more or less be translated into talk of properties as what is multiple realized and what does the multiple realizing. This is especially so if one thinks of kinds as explanatory properties in a theory or, similarly, that there is a close connection between the genuine properties and the kinds. Second, however, when discussing Polger and Shapiro on compositional variation and multiple realization, I will frame the discussion in terms of kinds so as to not beg any questions here one way or the other. In Sect. 5, I will speak more indiscriminately of properties or kinds, since I am confident that the modest point that I wish to make in that context is insensitive to this issue, and the material that I discuss in that context—Gillett’s (2003) response to Shapiro (2000)—agrees with me on this point (see fn. 18 and fn. 21). I am indebted to an anonymous referee for raising this issue.
For similar ideas, see Couch (2009).
See fn. 4.
In addition to the Taxonomy Relativity and Relevant Differences conditions, Polger and Shapiro argue that multiple realization requires that the S2 variation “must be distinct from the S1 intra-kind variation” across those systems—as, for example, the physical differences that a pair of waiter’s corkscrews may exhibit in virtue of having different length levers may correspond to differences with respect to how they perform the corkscrew function (2016, p. 67). My reason for setting aside this “Inter/Intra Kind Variation” condition is twofold. First, it is the Relevant Differences condition that most centrally raises issues for compositionally-based examples of multiple realization. Second, while I cannot discuss the issue here, I believe that the Inter/Intra Kind Variation condition can be shown to be problematic and unmotivated. For discussion of this condition, see especially Shapiro (2008). See fn. 13 for further discussion of the Inter/Intra Kind Variation condition and its salience to compositionally-based multiple realization.
Despite disagreeing about the significance of compositional variation for multiple realization, Aizawa and Gillett are in broad agreement with Polger and Shapiro on this point, noting that even if a psychological property is multiply realized at the microphysical level, it may not be multiply realized at the physiological level (2009a, p. 189; 2009b, p. 550).
See, for example, Polger and Shapiro (2016, pp. 18–32).
That is, compositional properties can play a role in explaining how an item is able to play the corkscrew function, but color properties cannot. To foreshadow the remarks below, it is consistent with this that certain theories—say, a theory that focuses on gross mechanical principles—may regard composition and color as equally irrelevant to corkscrew functioning.
It might seem that even if the considerations here show that compositional variation in kind across systems will frequently pass the Relevant Differences Condition for multiple realization, the present case (and those discussed shortly) nonetheless fail the Inter/Intra Kind Variation condition, according to which the lower-level S2 variation “must be distinct from the S1 intra-kind variation” across the systems of interest (see fn. 8). I do not think that this is the case, however. The reason is that in the present case, the assumption is that the compositional differences in kind do not map onto higher-level functional differences—the assumption is that the differently composed corkscrews are the same with respect to how they perform the corkscrew function or, in any case, that the differences in composition do not correlate with functional differences in the way that the Inter/Intra Kind Variation condition rules against. For example, in the present case, the compositional differences do not correlate with functional differences in the way that a pair of waiter’s corkscrews with somewhat different length levers may differ in corkscrew functioning, and differ precisely in a way that correlates with the differences in the length of the levers. It is true that from the point of view of the science of kitchen instruments S1, the compositionally different corkscrews are not different in kind and that the differences between the corkscrews are in this sense mere “individual differences.” But this is consistent with the case meeting the Inter/Intra Kind Variation condition, which specifically rules against the lower-level kind differences mapping onto higher-level individual differences; likewise, the mere fact that S1 does not recognize the compositional differences as differences in kind is to be expected and, indeed, is required for there to be a case of multiple realization on the Polger–Shapiro account, as the account supposes that multiple realization requires sameness of kind under S1. I am indebted to an anonymous referee for raising this issue.
See fn. 4.
Thus while Gillett marks that Shapiro (2000) focuses on kinds in discussing multiple realization (as Shapiro and Polger (2012) and Polger and Shapiro (2016) later would as well), he insists that his diagnosis in terms of differing views on the metaphysics of property realization “can be translated into such ‘kinds’” (2003, p. 592). See fn. 4 for related discussion.
See Endicott (2011). I disagree with Polger and Shapiro’s (2008) claim that (D) cannot even make sense of multiple realization since (D) takes realization to be a relation between property instances but instances are not repeatable. Part of the reason is that while (D) takes realization to be a relation between instances, it nonetheless makes reference to the properties that are instantiated and the conditions for being an instance of some such property; for discussion, see Endicott (2010).
(D–MR) does not suppose that in the context of evaluating multiple realization theses, judgments of sameness and difference ought to be indexed to specific theories. However, this can be incorporated into (D–MR) as bearing on the sameness of realized property and the difference of realizer properties. Because of this, I think that Polger’s suggestion that Gillett treats being an eye as multiply realized across human and octopus eyes because he fails to index multiple realization theses to specific theories is implausible (Polger 2008, pp. 542–3). Further, I do not think that (D-MR) trivializes the issue of multiple realization, at least not obviously, as Polger and Shapiro suggest (2016, pp. 38–9). For example, Gillett’s view can incorporate a relevance condition by appealing to the requirement in (D) that realizer properties are those that contribute powers in virtue of which some entity has those powers associated with a realized property. Whether this suffices to rule against all potential cases of “trivial” multiple realization may depend on the conditions under which some part of a whole contributes powers in virtue of which the whole has the powers associated with some property, and the extent to which trivial differences in composition suffice for differences with respect to those properties of the parts of a whole in virtue of which that whole has the relevant powers. Finally, I have framed these as theses about either kinds or properties. While there may be contexts in which regarding one or the other as the proper relata of what is realized and/or what is multiply realized is important (see fn. 4), explaining disagreement over the significance of compositional variation for multiple realization phenomena is not one of them—Gillett (2003) himself supposes that this issue can here be set aside (see fn. 18), and my reasons for questioning Gillett’s diagnosis do not turn on this choice point. Specifically, my claim that Gillett’s diagnosis cannot explain the relevant judgments regarding (1), (2) and (3) does not turn on whether it is properties or kinds that are what is realized and/or multiply realized.
To be fair, Gillett offers his diagnosis simply as explaining why some have been inclined to deny (3). However, when evaluating the plausibility of a diagnosis of the sort that Gillett proposes—that certain positions have been premised on an implicit commitment to some more basic, yet controversial, position—one should consider how other, related theses have been viewed.
See fn. 4.
See fn. 1.
I would like to thank Gerardo Viera, as well as the students in my Spring 2017 Metaphysics of Mind seminar at Tulane, for helpful discussion. I would also like to thank three anonymous referees at Synthese for helpful comments and constructive criticism.
References
Aizawa, K., & Gillett, C. (2009a). The (multiple) realization of psychological and other properties in the sciences. Mind and Language,24, 181–208.
Aizawa, K., & Gillett, C. (2009b). Levels, individual variation, and massive multiple realization in neurobiology. In J. Bickle (Ed.), The oxford handbook of philosophy and neuroscience. Oxford: Oxford University Press.
Aizawa, K., & Gillett, C. (2011). The autonomy of psychology in the age of neuroscience. In P. McKay Illari, F. Russo, & J. Williamson (Eds.), Causality in the sciences. Oxford: Oxford University Press.
Block, N. (1978). Troubles with functionalism. In C. W. Savage (Ed.), Minnesota studies in the philosophy of science (Vol. 9). Minneapolis: University of Minneapolis Press.
Block, N. (1980). Introduction: What is functionalism? In N. Block (Ed.), Readings in philosophy of psychology (Vol. 1). Cambridge, MA: Harvard University Press.
Boyd, R. (1980). Materialism without reductionism: What physicalism does not entail. In N. Block (Ed.), Readings in philosophy of psychology (Vol. 1). Cambridge, MA: Harvard University Press.
Clapp, L. (2001). Disjunctive properties: Multiple realizations. The Journal of Philosophy,98, 111–136.
Couch, M. (2009). Multiple realization in comparative perspective. Biology and Philosophy,24, 505–519.
Endicott, R. (2010). Realization, reductios, and category inclusion. The Journal of Philosophy,107, 213–219.
Endicott, R. (2011). Flat versus dimensioned: The what and how of functional realization. Journal of Philosophical Research,36, 191–208.
Fodor, J. (1974). Special sciences (or: The disunity of science as a working hypothesis). Synthese,28, 97–115.
Gillett, C. (2002). The dimensions of realization. Analysis,62, 316–323.
Gillett, C. (2003). The metaphysics of realization, multiple realizability, and the special sciences. The Journal of Philosophy,100, 591–603.
Gillett, C. (2007). Understanding the new reductionism: The metaphysics of science and compositional reduction. The Journal of Philosophy,104, 193–216.
Gillett, C. (2016). Reduction and emergence in science and philosophy. Cambridge: Cambridge University Press.
Heil, J. (2003). From an ontological point of view. Oxford: Oxford University Press.
Kim, J. (1992). Multiple realization and the metaphysics of reduction. Philosophy and Phenomenological Research,52, 1–26.
Kim, J. (1998). Mind in a physical world. Cambridge, MA: The MIT Press.
Kim, J. (2005). Physicalism, or something near enough. Princeton: Princeton University Press.
Lewis, D. (1994). Reduction of mind. In S. Guttenplan (Ed.), A companion to the philosophy of mind. Oxford: Blackwell.
Melnyk, A. (2003). A physicalist manifesto. Cambridge: Cambridge University Press.
Morris, K. (Forthcoming). Physicalism deconstructed: Levels of reality and the mind-body problem. Cambridge: Cambridge University Press.
Polger, T. (2008). Two confusions concerning multiple realization. Philosophy of Science,75, 537–547.
Polger, T. (2009). Evaluating the evidence for multiple realization. Synthese,167, 457–472.
Polger, T., & Shapiro, L. (2008). Understanding the dimensions of realization. The Journal of Philosophy,105, 213–222.
Polger, T., & Shapiro, L. (2016). The multiple realization book. Oxford: Oxford University Press.
Putnam, H. (1967). Psychological predicates. In W. Capitan & D. Merrill (Eds.), Art, mind and religion. Pittsburgh: University of Pittsburgh Press.
Putnam, H. (1975). Philosophy and our mental life. In Mind, language, and reality. Cambridge: Cambridge University Press.
Richardson, R. (1979). Functionalism and reductionism. Philosophy of Science, 46, 533–558.
Shapiro, L. (2000). Multiple realizations. The Journal of Philosophy,97, 635–654.
Shapiro, L. (2004). The mind incarnate. Cambridge, MA: The MIT Press.
Shapiro, L. (2008). How to test for multiple realization. Philosophy of Science,75, 514–525.
Shapiro, L., & Polger, T. (2012). Identity, variability, and multiple realization in the special sciences. In C. Hill & S. Gozzano (Eds.), New perspectives on type identity. Cambridge: Cambridge University Press.
Shoemaker, S. (2001). Realization and mental causation. In C. Gillett & B. Loewer (Eds.), Physicalism and its discontents. Cambridge: Cambridge University Press.
Shoemaker, S. (2007). Physical realization. New York: Oxford University Press.
Sober, E. (1999). The multiple realizability argument against reductionism. Philosophy of Science, 66, 542–564.
Wilson, J. (1999). How superduper does a physicalist supervenience need to be? The Philosophical Quarterly,49, 33–52.
Wilson, J. (2011). Non-reductive realization and the powers-based subset strategy. The Monist,94, 121–154.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Morris, K. Multiple realization and compositional variation. Synthese 197, 2593–2611 (2020). https://doi.org/10.1007/s11229-018-1837-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11229-018-1837-1