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Persistence, Ontic Vagueness and Identity: Towards a Substantialist Four–dimensionalism

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Metaphysica

Abstract

Four-dimensionalism, the stage theory version in particular, has been defended as the best solution for avoiding vagueness in regards to composition, persistence and identity. Stage theory is highly problematic by itself, and the two views usually packed with it, unrestricted composition and counterpart theory, are a heavy burden. However, dispensing with these two views, four-dimensionalism could avoid vague persistence by issuing a criterion that would establish sharp temporal boundaries for the existence of genuine entities (simples, molecules and living organisms). This would avoid vague existence and vague identity, but in a way that is still compatible with endurantism. Nevertheless, a minimal (substantialist) four-dimensionalism, a worm perdurantist ontology, would fit better with the unique way in which organisms persist: by retaining both identity and intrinsic change.

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Notes

  1. Williamson (2003, 700) chooses this last category as the most embracing for ontological vagueness.

  2. Stalnaker (1988). The semantic conception of vagueness is defended in Lewis (1986, 212).

  3. Van Inwagen claims: “Those who believe that people are a certain special type of four-dimensional object will hold that “Alpha” is a name for a segment of a four-dimensional object and that “Omega” is also a name for a segment of this object. Whether “Alpha” and “Omega” are names for the same segment—namely, the whole thing—will depend on whether the predicate “is an enduring thing” applies to the whole thing or not. This predicate (they will say) is vague” (1990a, 243).

  4. One classical defence is proposed by Heller (1984; 1990).

  5. Here we can rest comfortably: if space and time are discrete, a spatio-temporal part of an object is the space-matter region occupied by it at an instant.

  6. Williamson and Fara (2005) have attacked counterpart theory on technical grounds. I will limit to the philosophical misgivings of counterpart theory. If it is semantically deficient, this is so much the worse for it.

  7. I agree with Sider that “the four-dimensionalist... claims merely that temporal parts exist, not that one vocabulary is analytically prior to the other”, and that the fact that we cannot individuate stages without making reference to continuants, whereas the converse does not hold “lends no support whatsoever to its metaphysical conclusion that temporal parts do not exist” (210–211). But I think this fact supports that four-dimensional wholes are ontologically (not just epistemically) more basic than their parts; that continuants are not supervenient on their temporal parts.

  8. Presumably each sum of continuous temporal parts. But for Lewis, as any sum whatever of temporal parts does make up an object, a sum of discontinuous temporal parts of a (for us single) table would also make up an object. Now this “object” is something very different from a standard table. It is not only a “table” with intermittent existence (something admissible if that table were periodically dismantled and mounted again) but an intermittently existing “table” while there is also an ordinary table existing all the time in the same place!

  9. Hawley (2001, 4.11). Certainly, indeterminacy in causality is currency, whereas indeterminacy in identity is awkward. Later Hawley says: “So far as stage and perdurance theory go, much depends, I think, upon the role of natural objects and “suitable relations”... If there is a single relation or cluster of relations which binds together the stages of natural objects, then we must offer either an ontic or an epistemic account of apparent vagueness in persistence. If that relation can enter into vague states of affairs, then vagueness in persistence may be ontic. If, on the other hand, such ontic indeterminacy is impossible, then vagueness in persistence must be epistemic—either two stages are stages (or temporal parts) of the same object, or they are not, even if we cannot know this” (137). My argument will be: there are natural objects; these are atoms, molecules and living organisms; the relation between the temporal parts of any of these is identity; identity cannot be indeterminate; so when the persistence of a natural object is vague, the vagueness involved is epistemic, otherwise the object is not natural after all. All other cases of vague persistence (planets, mountains, clubs, railroads) are due to semantic indecision; that vagueness is “ontic” in a pickwickian sense.

  10. There is a debate concerning whether philosophers defending this position are obliged to provide criteria of persistence, or are they able to rest content by saying that persistence is an irreductibly brute fact. Something similar happens concerning composition and identity referred to spatial parts: for some philosophers (Merricks, Makrosian) there can be brute, non-reductible composition; for others (Lewis, Sider) composition is always supervenient on certain relations.

  11. It is interesting that even someone so Humean like David Lewis (1983) has felt the need to resort to natural properties in order to account for laws of nature and other phenomena. And natural properties are intrinsic properties of natural objects.

  12. Of course, in problematic cases, where massive replacement of parts or fission or fusion occurs there would be some semantic indeterminacy, but this would simply mirror the ontological indeterminacy affecting the ship(s). There would be two or three ships involved in cases like Theseus’s ship story, not millions!

  13. Interestingly, Hudson (2000, 556) says that persons are maximal concepts, and so no subclass of the class that composes a person can be a person, but this is not the case with artefacts, where the problem of the many is unavoidable, and Hudson adopts Lewis’s solution: that there are infinitely almost identical ships (tables, cats, etc.).

  14. Hudson (2000, 558) claims that epistemicism is useful to avoid the problem of the many for objects corresponding to maximal concepts and when one object is a proper part of the object, since maximality is a non-arbitrary property that permits to single out an object (the maximal) as the only object around that is for instance a person. But when none of the objects involved is a proper part of the other, maximality does not play any role, and epistemicism is unuseful to avoid the problem of the many.

  15. Atoms are to be included in the same category as molecules, since both are natural composites with cut-off temporal boundaries. If some elementary particles were eternal, their temporal limits would also be non-fuzzy.

  16. Admittedly, things can be more difficult to establish within lower organisms, but there is a case for them being liable to sharp temporal boundaries. It is more dubious whether organisms have spatially sharp boundaries. I will claim that their spatially fuzzy boundaries are unproblematic as long as they affect to inessential parts. Thus, vagueness concerning spatial boundaries is compatible with sharpness concerning temporal ones.

  17. This assertion can sound question begging, for it is the persistence of changing entities that is at stake. Mereological essentialism has it that persistence and a change of parts are incompatible; so if organisms or persons are true continuants it must be in virtue of their true and unchangeable nature: a soul. But it is highly implausible that even souls are unchangeable in the required sense, and so the upshot would be that there is no true persistence whatever. It could be so, but this would be a tremendously revisionist (and nihilist) position. Our point is: let’s concede there are some persistent entities, but which ones and why?

  18. E. J. Lowe (2002, 33) denies this, asserting that when a part x finishes composing a whole A and begins to compose a new whole B, x “gets” a new identity, and can no longer form part of A again as the original component it once was. I find this an unpersuasive way to forbid by decree intermittent existence: a certain collection of pictures seems to be again the same collection it was after the robbery of a picture once the picture is recovered (in perfect condition), no matter whether in the meantime the picture robbed formed part of another collection or it was simply hidden alone in a store.

  19. The word ‘worm’ suggests the idea of something that is truly evolving (getting bigger, older, changing chemical composition etc.) not just changing spatio-temporal position, like molecules.

  20. When a macro-molecule changes its properties by changing its three dimensional shape, even if keeping the same atoms, it is a different molecule. For molecules not only their parts are essential, but their distribution in space is too. This is a sort of topological essentialism.

  21. Here biology is the one to decide. If there were no biological difference just after fission there would be no basis to say that one is the original and the other a replica. However, whether there are differences and how relevant they are, is for biologists to determine.

  22. Certainly, I can survive without my heart, with an artificial heart or the heart of a donor. I mean I cannot survive naturally without my heart, while I can without this or that bacteria. The bacteria and I are independent of each other in a sense in which my heart and me are not: by nature (cf. van Inwagen 1990a, sec. 14).

  23. It is interesting that most potentially dangerous artificial objects have legal (and quite precise) identity criteria: cars, trains, planes, guns, tanks, etc. With chairs, pens, shirts, etc. we do not need anything similar.

  24. As common sense concerns, it seems to me equally bizarre to claim that ships, etc. do not exist as it is to claim that there really are billions of ships where we speak of a single ship. But as ontology is concerned, the right answer is that ships, etc., as single persisting but changing individual entities, do not exist.

  25. It is not the case that when we say “that ship is such and so” we are referring to nothing. We are referring to some or other collection of temporal parts arranged ship-waise. And all adequate candidate collections share most of their temporal parts.

  26. Van Inwagen (2002) has argued that the number of objects has to be determinate (at least in the worlds in which identity is non-vague), but these objects are “anything that can be the value of a variable” linked by (ordinary, unrestricted) quantifiers. Nevertheless, unrestricted quantifiers range over the basic components of reality, which for Smith are possibilia. Ships, tables or mountains are only derivative composites, and so their number in a given world and time can be indeterminate, while the number of possibilia is determinate.

  27. A tree about to die is almost dead, but alive, even if only a few cells remain active. Usually, when we declare a tree dead it is still alive, but in so bad condition that it cannot (biologically) recover. As for ordinary purposes, the tree is dead; for ontology, it is alive (as long as some of its cells are still working).

  28. If we removed the steering-wheel instead, we would be more reluctant to say that the car exists at 98% degree: since the car cannot work without it, maybe a case could be made for the non-existence of the car.

  29. The point is: if you find a helm you can say, “look, this is the 1% of a ship”; but if you find a pond it is improper to say: “look, this is the 1% of a lake” (or the 1/100.000 of a sea). The helm is essentially part of something, while the pond is complete as it is.

  30. They can consist of temporal parts, but each temporal part is not a mere sum of spatial components. That, contrary to Sider’s claim, not all cases of vague composition entail vague existence, is argued by Merricks (2005, 618) appealing to cases like the one just mentioned. Nevertheless, that vague composition sometimes entails vague existence continues to be a problem.

  31. When a portion of a nail of mine is hanging it could be argued that it is vague whether this portion is a part of me or not (although to me, it is). This cannot happen with essential parts like the heart or the brain: if I can survive with the organ connected as it currently is, it is definitely a part of me, and otherwise it is not. However, it could be more than that. When we admit that it can be vague whether a particular atom or cell or hair forms part of a deer at a given time, but not whether the deer is alive or dead, are we not saying that the spatial boundaries of substances allow for some fuzziness while the temporal parts don’t?

  32. Haslanger (2003, 326-327) remarks that there is a big methodological question concerning what could be accepted as a genuine theory of persistence as opposed to a theory that denies persistence. Later, she adds: “The stage theory asserts that objects persist without themselves being present at different times... So at the level of ordinary speech the identity condition [if an object persists through a change, then the object existing before the change is one and the same object as the one existing after the change] is preserved, even if at the ontological level the identity condition is violated... To my mind, however, this strategy strains the limits of credibility” (335). In the end, ‘persistence’ means something quite different for stage theorists.

  33. Mc Kinnon (2003) has argued that there is nothing incoherent in the idea of simples with vague spatial boundaries. Even if so, they would not be liable to vague existence (unless this vagueness could affect their temporal boundaries too).

  34. As has argued Makrosian 1998.

  35. Recall that for Hawley it is non-supervenient, but possibly gradual.

  36. Merricks offers a reduction of Sider’s position: his “prohibition against vague existence is itself a reason to think that the feature of composite objects cannot be vague. For suppose that, necessarily, a composite exists just in case an irreductible feature is exemplified. Then its being vague whether such a feature is exemplified implies that it is vague whether a composite exists. But vague existence is out. So the irreductible feature cannot be vague” (Merricks 2005, 632-33). That is fine, and my candidate for the irreductible feature is life in the case of organisms, and the emergence of new properties in the case of molecules.

  37. That it fits better with relativity theory, since space and time are treated uniformly; that it can solve the problem of temporary intrinsics; that it can accommodate the actual (not just possible) existence of time machines at sub-microscopic levels, etc.

  38. If a dual ontology of persistence were viable, then we could claim that simples and molecules endure, while organisms perdure. In case it is preferable to adopt a single ontology of persistence for static and dynamic substances, we should opt for perdurantism, as atoms and molecules simply exist rather than persist. If you accept Merrick’s (plausible) thesis that perduring and enduring entities are incompatible, your ontology must be either 4-D or 3-D. This is a far-reaching debate. We would feel more comfortable with temporal parts for atoms and molecules if they also had a physical “internal clock” in the sense in which organisms undoubtedly have a biological clock, with a deadline inscribed from the very beginning. This is something for physicists to determine.

  39. Merricks (2005) upshot is that ontological vagueness is not a big problem, and so four-dimensionalism is unmotivated as the solution to it.

  40. Of course, with this move four-dimensionalism does no longer provide a counterpart theoretic solution of the problem of trans-world identity for true individuals. However, trans-world identity is also a problem for endurantism.

  41. Hudson (2000) is a good sample of the problems one gets into because of universal composition. Rea (1998) claims that if we reject universal composition we have to reject also the existence of artefacts. This is so (unless we are ready to face vague composition, and vague existence), but I think the rejection of artefacts in ontology is far more plausible that the admission of gerrymandered “objects”.

References

  • Broome, J. (1984). “Indefiniteness in Identity”. Analysis, 1984, 44; 6–12.

    Article  Google Scholar 

  • Hawley, K. (2001). How Things Persist. Oxford, Clarendon.

    Google Scholar 

  • Heller, M. (1984). “Temporal Parts of Four-Dimensional Objects”. Philosophical Studies, 46; 323–334.

    Article  Google Scholar 

  • Heller, M. (1990). The Ontology of Physical Objects. Four-dimensional Hunks of Matter. Cambridge, Cambridge University Press.

    Google Scholar 

  • Heller, M. (1993). “Varieties of Four-Dimensionalism”. Australasian Journal of Philosophy, 71; 47–57.

    Article  Google Scholar 

  • Haslanger, S. (2003). “Persistence Through Time”. In The Oxford Handbook of Metaphysics, Oxford U.P.; 315–356.

  • Hudson, H. (2000). “Universalism, Four-dimensionalism and Vagueness”. Philosophy and Phenomenological Research, 60; 547–560.

    Article  Google Scholar 

  • Lewis, D. (1983). “New Work for a Theory of Universals”. Australasian Journal of Philosophy; 343–377.

  • Lewis, D. (1986). On the Plurality of Worlds. Oxford, Blackwell.

    Google Scholar 

  • Lowe, E.J. (2002). A Survey of Metaphysics. Oxford, Clarendon.

    Google Scholar 

  • Makrosian, N. (1998) “Brutal Composition”. Philosophical Studies, 92; 211–249.

    Article  Google Scholar 

  • McKinnon, N. (2003) “Vague Simples”. Pacific Philosophical Quarterly, 84; 394–397.

    Article  Google Scholar 

  • Merricks, T. (2005). “Composition and Vagueness”. Mind, 114; 615–637.

    Article  Google Scholar 

  • Nadler, S. (ed.) (1993): Causation in Early Modern Philosophy: Cartesianism, Occasionalism, and Preestablished Harmony. Pennsylvania State Uni. Press.

  • Rea, M. (1998): “In Defense of Mereological Universalism”. Philosophy and Phenomenological Research, 58; 347–360.

    Article  Google Scholar 

  • Sider, T. (2001). Four-dimensionalism, Oxford, Clarendon, 2001.

  • Smith, N.J.J. (2005). “A Plea for Things that Are not Quite All There. Or Is There a Problem about Vague Composition and Vague Existence”. Journal of Philosophy, CII; 381–421.

    Google Scholar 

  • Stalnaker, R. (1988). “Vague Identity”. In Austin, D.F.: Philosophical Analysis. A Defense by Example. Dordrecht, Reidel.

    Google Scholar 

  • Thompson, J.J. (1983). “Parthood and Identity across Time”. The Journal of Philosophy, 80; 201–220.

    Article  Google Scholar 

  • Van Inwagen, P. (1990a). Material Beings. Ithaca, Cornell U.P.

    Google Scholar 

  • Van Inwagen, P. (1990b). “Four Dimensional Objects”. NOUS, 24; 245–255.

    Google Scholar 

  • Van Inwagen, P. (2000). “Temporal Parts and Identity across Time”. The Monist, 83; 437–459.

    Google Scholar 

  • Van Inwagen, P. (2002). “The Number of Things”. Philosophical Issues, 12; 176–196.

    Article  Google Scholar 

  • Varzi, A. (2003). “Naming the Stages”. Dialectica; 387–412.

  • Williamson, T. (2003). “Vagueness in Reality”. In The Oxford Handbook of Metaphysics, Oxford U.P.; 691–711.

  • Williamson, T. & Fara, M. (2005). “Counterparts and Actuality”. Mind, 114; 1–30.

    Article  Google Scholar 

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Correspondence to Enrique Romerales.

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Romerales, E. Persistence, Ontic Vagueness and Identity: Towards a Substantialist Four–dimensionalism. Int Ontology Metaphysics 9, 33–55 (2008). https://doi.org/10.1007/s12133-007-0020-9

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