Abstract
The debate over persistence is often cast as a disagreement between two rival theories—the perdurantist theory that objects persist through time by having different temporal parts at different times, and the endurantist theory that objects persist through time by being wholly present at different times. This way of framing the debate over persistence involves both an important insight and an important error. Unfortunately, the error is often embraced and the insight is often ignored. This paper aims to correct both of these mistakes, and thus clarify the debate over persistence.
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Notes
The standard definition of a temporal part is given by Ted Sider: “x is an instantaneous temporal part of y at instant t = df (i) x exists at, but only at t, (ii) x is part of y at t, and (iii) x overlaps at t everything that is part of y at t” (2001: 205). As Sider points out, this definition of an instantaneous temporal part can be generalized to cover extended temporal parts as well (ibid: 206).
Hawley (2010: Sect. 2).
Crisp (2003: 216).
Effingham (2009: 301). Effingham briefly considers the suggestion that perdurantism should be understood as a view about how things persist (rather than a view about what things exist), but dismisses this idea as “murky” (ibid).
For other accounts along these lines, see Crisp (2003: 216), Crisp and Smith (2005: 319), Effingham (2009: 301), Gilmore (2008: 1224), Heller (1984: 325–329), Hudson (2001: 58–59), Markosian (1994), Markosian and Carroll (2010: 172), McGrath (2007: 730), McKinnon (2002), Merricks (1999), Miller (2009: 216), Parsons (2007), Sider (2001: 59), van Inwagen (1990), Wasserman (2004: 75), and Wikipedia (“Perdurantism or perdurance theory is a philosophical theory of persistence… The perdurantist view is that an individual has distinct temporal parts throughout its existence.”).
One could, for example, take facts about temporal parts to be grounded in facts about temporal continuants, rather than vice versa. This would be a view on which temporal wholes are more basic than temporal parts.
There are at least two other things to say in support of the explanatory conception. First, perdurantists have always been guided by an analogy between space and time and, in the case of space, it is natural to think that objects exist in different places because they have different parts in those places. Sider, for example, writes that “US Route 1 extends from Maine to Florida by having subsections in the various regions along its path.” (2001: 2, emphasis mine) But in that case, we should say the same thing about time—objects exist at different times by having different temporal parts at those times.
A second reason to prefer the explanatory conception is that philosophers have historically used explanatory terms when describing the view. Russell (1914: 112), for example, says that persisting objects are “defined” by temporal parts. Quine (1950: 621) says that persisting objects are “constituted” by temporal parts. And Chisholm says that an object composed of temporal parts would be an “ens per alio”—an entity that “is what it is in virtue of the nature of other things” (1976: 104). So precedent also provides some support for the explanatory account. (In fact, even Sider sometimes uses explanatory language when describing the perdurantist view—he say, for example, that perdurantism is a theory of “how” things persist through time (2001: 54, italics original).
To be fair, it is not clear that Lewis appreciated his own insight. In some cases, he formulated perdurantism as an ontological thesis (1983: 76–77), and in many other cases he formulated philosophical theories in terms of necessary and sufficient conditions. For example, Lewis formulates the counterfactual analysis of causation as the view that “one event is a cause of another iff there exists a causal chain leading from the first to the second,” where a causal chain is a series of events linked by counterfactual dependence (Lewis 1973: 563). He formulates the conditional analysis of dispositions as the view that “Something x is disposed at time t to give response r to stimulus s iff, if x were to undergo stimulus s at time t, x would give response r” (Lewis 1997: 143). And he formulates his account of counterfactuals as the view that “\(A\; \square\!\!\to C\) is non-vacuously true iff C holds at all the closest A-worlds” (Lewis 1973: 561).
On the present proposal, all of these formulations involve a fundamental mistake about the nature of philosophical theories. Theories are not ontological theses, or biconditional claims, or lists of necessary and sufficient conditions (although a given philosophical theory may entail all of these things). Rather, philosophical theories are theories about what grounds what (Schaffer 2009). So, for example, if Lewis’s theory of counterfactuals is to be a genuine theory of counterfactuals, it should not be formulated as the view that counterfactual truths are correlated with certain facts about comparative similarity. Rather, it should be formulated as the view that counterfactual truths are grounded in certain facts about comparative similarity: \(A\; \square\!\!\to C\) is non-vacuously true only if, and because, C holds at all the closest A-worlds. Similar remarks apply to the conditional analysis of dispositions, the counterfactual treatment of causation, and all other theories of this kind.
This definition would be too weak, since it would classify perduring objects as being wholly present whenever they exist (since everything that is a part of a perduring object at a time will exist at that time).
This definition would be too strong, since it would imply that no humans are wholly present now (since all of us have had parts in the past which no longer exist).
The problem with this definition is that it would be inconsistent with what many endurantists want to say in cases of co-location. Suppose, for example, that an ordinary lump of clay is created at t1, formed into a statue at t2, and then rolled up into a ball at t3. According to many endurantists, this story involves at least two objects—a lump of clay and a statue. But, if the statue and lump share all of the same parts from t2 until t3 then, given the standard axioms of mereology and the standard definition of ‘temporal part’, it will turn out that the statue is a temporal part of the lump from t2 to t3.
For example, (WP) easily avoids the worry raised in fn. 15. One can admit that the statue is a temporal part of the lump from t2 to t3 without saying that the lump exists at those times because of that part. Indeed, the more natural thing to say in this case is that the statue’s existence and features are to be explained by reference to the lump, rather than the other way around. This way of looking at things is perfectly consistent with (WP).
This qualification is important. See fn. 20.
Here is one problem. Many perdurantists accept unrestricted composition, and therefore believe that any collection of random temporal parts will have sum, even if those parts do not stand in any causal relations to each other. If having temporal parts at different times is sufficient for existing at different times, and if existing at different times is sufficient for persistence, then it will follow that these sums persist through time without the right kind of causal dependence.
References
Balashov, Y. (2000). Enduring and perduring objects in Minkowski space–time. Philosophical Studies, 99, 129–166.
Carroll, J. W., & Markosian, N. (2010). An introduction to metaphysics. Cambridge: Cambridge University Press.
Chisholm, R. M. (1976). Person and object. Chicago: Open Court.
Crisp, T. (2003). Presentism. In M. Loux & D. W. Zimmerman (Eds.), The Oxford handbook of metaphysics. Oxford: Oxford University Press.
Crisp, T., & Smith, D. (2005). ‘Wholly present’ defined. Philosophy and Phenomenological Research, 71, 318–344.
Effingham, N. (2009). Persistence, composition and identity. In R. Le Poidevin, et al. (Eds.), The Routledge companion to metaphysics. New York: Routledge.
Fine, K. (2011). Guide to ground. In F. Correia & B. Schnieder (Eds.), Metaphysical grounding. Cambridge: Cambridge University Press.
Gilmore, C. (2008). Persistence and location in relativistic spacetime. Philosophy Compass, 3, 1224–1254.
Hawley, K. (2001). How things persist. Oxford: Oxford University Press.
Hawley, K. (2010). Temporal parts. In E. Zalta (Ed.), The Stanford encyclopedia of philosophy. http://plato.stanford.edu/entries/temporal-parts/.
Hawthorne, J. (2008). Three-dimensionalism vs. four-dimensionalism. In T. Sider, J. Hawthorne, & D. W. Zimmerman (Eds.), Contemporary debates in metaphysics. Oxford: Blackwell.
Heller, M. (1984). Temporal parts of four dimensional objects. Philosophical Studies, 46, 323–334.
Hirsch, E. (2009). Ontology and alternative languages. In D. Chalmers, D. Manley, & R. Wasserman (Eds.), Metametaphysics. Oxford: Oxford University Press.
Hudson, H. (2001). A materialist metaphysic of the human person. Ithaca: Cornell University Press.
Jackson, F. (1994). Metaphysics by possible cases. The Monist, 77, 93–110.
Lewis, D. (1973). Causation. Journal of Philosophy, 70, 418–446.
Lewis, D. (Ed.). (1983). Postscripts to “survival and identity”. In Philosophical papers, Volume I. Oxford: Oxford University.
Lewis, D. (1986). On the plurality of worlds. Oxford: Blackwell.
Lewis, D. (1997). Finkish dispositions. The Philosophical Quarterly, 47, 143–158.
Marksosian, N. (1994). The 3D/4D controversy and non-present objects. Philosophical Papers, 23, 243–249.
McCall, S., & Lowe, E. J. (2006). The 3D/4D controversy: A storm in a teacup. Noûs, 40, 570–578.
McCall, S., & Lowe, E. J. (2009). The definition of endurance. Analysis, 69, 277–280.
McGrath, M. (2007). Temporal parts. Philosophy Compass, 2, 730–748.
McKinnon, N. (2002). The endurance/perdurance distinction. Australasian Journal of Philosophy, 80, 288–306.
Merricks, T. (1999). Persistence, parts and presentism. Noûs, 33, 421–438.
Miller, K. (2005). The metaphysical equivalence of three and four dimensionalism. Erkenntnis, 62, 91–117.
Miller, K. (2009). Ought a four-dimensionalist to believe in temporal parts? Canadian Journal of Philosophy, 39, 619–647.
Parsons, J. (2007). Theories of location. Oxford Studies in Metaphysics, 3, 201–232.
Quine, W. V. O. (1950). Identity, ostention, and hypostasis. The Journal of Philosophy, 47, 621–633.
Russell, B. (1914). Our knowledge of the external world. London: Allen & Unwin.
Schaffer, J. (2009). On what grounds what. In D. Chalmers, D. Manley, & R. Wasserman (Eds.), Metametaphysics. Oxford: Oxford University Press.
Sider, T. (2001). Four-dimensionalism: An ontology of persistence and time. Oxford: Oxford University Press.
van Inwagen, P. (1990). Four-dimensional objects. Noûs, 24, 245–255.
Wasserman, R. (2004). Framing the debate over persistence. Metaphysica, 5, 67–80.
Acknowledgments
I thank Hud Hudson and an anonymous referee for this journal for comments on earlier versions of this paper. I also thank Western Washington University for professional leave during which time this paper was written.
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Wasserman, R. Theories of persistence. Philos Stud 173, 243–250 (2016). https://doi.org/10.1007/s11098-015-0488-z
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DOI: https://doi.org/10.1007/s11098-015-0488-z