RECENT WORK

ESSENTIALISM: PART 2

1. Ihe Mind-Body Problem

Perhaps the most controversial segment of Kripkes Naming and Necessip is its closing treatment of the mind-body problem. On essentialist grounds, he argues for the claim that no token mental event is identical with a physical event, that no mental event-type is identical with a physical event-type and that the mind is not identical with the body. In each case, Kripkes strategy is the same: to show that for a given mental item A (the mind or a mental event-type or a mental event-token) and for a given physical item B, purportedly identical with A, there is a property that A has essentially and that B does not or there is a property that B has essentially but A does not. Given this difference in essential properties, it follows that A is not identical with B after all. One such property is, according to Kripke, the property of being mental. A, the mental item has this property essentially or necessarily, but, Kripke, claims on intuitive grounds, B does not.2

In contrast to the formally similar Goliath case, in the mental-physical cases many philosophers have explored the matter of whether the intuitions of contingency that apparently lead to the claims of non-identity can be reconstrued in Kripkean fashion. Kripke himself takes up this matter and concludes that a reconstrual is not available and thus he stands by the claims of non-identity. However, without questioning Kripkes essentialist framework, many others have argued that, in at least some of the mental-physical cases, an appropriate reconstrual is available and thus, on this view, the relevant arguments for non-identity do not go through. In particular, some have defended a claim of token-token identity along these lines.3

1. Strictly, in the case of event-tokens and event-types, Kripke only draws conclusions for the type pain and for tokens of that type. But there seems to be no reason why his conclusions cannot be generdised.

2. Naming And Necessip, pp. 144-155; Identity and Necessity, pp. 98-101. 3. See Richard Boyd, Materialism Without Reductionism: What Physicalism Does Not Entail,

in Ned Block (ed.), Readings in Philosophy ofPTchology, vol. i (Harvard University Press, 1980) pp. 67--106 (see esp. pp. 83-85); Olaf Gjelsvik, A Kripkean Objection to Kripkes Argument against Identity Theories, Inquiy, vol. XXY (1987), pp. 435-450; and Colin McGinn, Anomalous Monism and Kripkes Cartesian Intuitions, in Block (ed.), Readings in Philosophy of Ppsychoolo~, vol. 1 , pp. 156-157. For related approaches, see Steven R. Bayne, Kripkes Cartesian Argument, Philosophia, vol. xviii (1988), pp. 265-269; Michael Della Rocca, Kripkes Essentialist Argument Against the Identity Theory, Philosophical Studies, vol. lxii (1993), pp. 101-1 12; Fred Feldman, Identity, Necessity, and Events, in Block (ed.), Readirgs in Philosopfy .f PgcholoQ, vol. 1, pp. 148-155; and Thomas Nagcl, The Vm Fmm Nowhm (Oxford University Press, 198G), pp. 46-49. Yablo defends some of the Kripkean arguments on this matter in The Real Distinction between Mind and Body, Canadian journal of Phihsoply, Supplementary Volume xvi (1 990), pp. 149-20 1, and Is Conceivability a Guide to Possibility?, Philoso& and Phenommological Research, vol. lii (1 993), pp. 1-42.

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2. Awing for Essmtialist Claim

So far 1 have discussed attempts to defend the view that modal contexts are referentially transparent and related attempts to draw conclusions of non- identity from particular essentialist claims. None of this, however, goes to show how, if at all, one might offer positive arguments for essentialist claims. If one is to rebut the Quinean charge that there is no principled basis for dividing a things properties into the essential and the non-essential, one must provide such arguments

To meet this challenge, many essentialists have put forth a general form of argument which purports to establish essentialist conclusions for a wide variety of things. I will investigate the effectiveness of such arguments by explaining how essentialists have used this strategy to argue, in particular, for the essentiality of rigi in.^

Assume that a particular oak tree, T1, originates from a certain acorn A. Could T1 have originated from a wholly different acorn, B? If so, then Tls origin is not essential to it. Since there would be no reason to see T1 as special in this regard, we would also have reason to conclude that origin is not essential to trees and, perhaps, organisms in general and other objects as well.

To see whether or not T1 could have originated from B instead of A, assume that originating from B is, in fact, a possibility for T1. What follows from this assumption? Lets call the actual world (which is, as we stipulated, a world in which T1 originates from A) wl. Consider a world in which TI does not originate from A, but from B instead and, more particularly, consider a world, w2, which is very much like wl apart from the fact that in w2 T1 originates from B instead of A. Thus, in w2, T1 comes into existence at the same time and place as it does in wl and, moreover, is made of as much of the same matter that it is made of in wl as is compatible with its originating from B instead of A. Further, lets stipulate that in w2 no oak tree at all originates from A. That there is such a possible world appears to follow from our assumption that T1 might have originated from B instead of A.

Now the fact that an oak tree develops from B at a particular location and time does not preclude a different oak tree from originating from A at the same time, but at a different, though nearby, place. In particular, the fact that T1 is the oak tree that develops from B at a certain place and time does not preclude the possibility that at some nearby location a different oak tree simultaneously develops from A. The relevant claim here is:

4. For arguments in the spirit of the argument I am about to give, see Forbes, Origin and Identity, Philosophical Studies, vol. xxxvii (1980), pp. 353-362, ?he Melaphysics of Modalip, Ch. 6, and In Defense of Absolute Essentialism; Kripke, .Naming and Necessip, note 56; Nathan Salmon, Reference and Essmce (Princeton University Press, 1981), Ch. 7; and Stephen Yablos review of Forbes 7h Metaphysics oJModalzp, Journal o f Philosop!y, vol. lxxxv (1988), pp. 329-337. For reasons of simplicity and clarity, my argument will not exactly match the presentation of their arguments. The general form of my argument is most similar to Van Cleves argument for the view that sets contain their members essentially (see Van Cleve, Why a Set Contains Its Members Essentially, Nous, vol. xix (1985), pp. 585-602).

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(1) If it is possible that T1 originates from B at a certain place and time, then it is also possible that TI originates from B at that place and time and a different oak tree originates from A simultaneously at a nearby location.

(1) is very plausible: the fact that a certain tree develops from a certain acorn does not, it seems, place restrictions on whether a dflirmt acorn can generate a tree as well at the same time in a nearby place. (Of course, the places cannot be too close together and the region as a whole must be able to support two trees, but it seems clear that these requirements can be met.)

Consider, then, a world, w3, in which T i originates from B and at a nearby location some other tree, T2, originates from A. Notice that w3 # w2 since in w2, as we stipulated, no oak tree develops from A, but this is not the case in w3.

Lets introduce now a further, intuitively very strong principle that is crucial in the argument for origin essentialism. Many essentialists share the intuition that an oak tree that originates from a certain acorn might have originated from that acorn at a different place, might have originated at a different time, might have been made of largely different matter, etc. What seems to be behind these intuitions is the intuition that if a given oak tree originates from a certain acorn, then being an oak tree that results from that acorn is, in any possible situation, sufficient for being that very tree. Features like location, time of existence, and constitution are seen as non-essential to a given oak tree once it is granted that in any possible situation being an oak tree that results from a particular acorn is sufficient for being that tree.5 As applied to the case of T1 and A, the intuition is:

(2) If T1 is an oak tree that originates from A, then in any possible situation, if x is an oak tree that originates from A, then x = T 1 .6

Now if one accepts (2) and the very plausible claim (l), and if one stipulates that

(3) In the actual world, T1 originates from A

then one can show that the assumption of

(4) TI might have come from B instead of A

leads to absurdity. On the assumption of (4), it follows from (1) that there is a possible world in which T1 originates from B and some other oak tree

5. Notice that the sufficient condition is being an oak tree that originates from a certain acorn and not simply being something that originates from a certain acorn. On the reasons for this, see Forbes,ne Met~plysics ofModali&, pp. 146-1 48.

6. (2) might need further refinement if it is possible for more than one oak tree to originate (at the same or different times) from the same acorn. For some of the needed qualifications, see Salmon, R$ience and Essence, Ch. 7.

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originates from A (w3 is such a world). But (2) and (3) together entail that there is no such possible situation. Thus, given (l), (2) and (3), we must conclude that (4) is false, i.e. that T1 could not have come from B. The form of the argument is quite simple. (2) and (3) entail that the consequent of (1) is false. Thus for (l), (2) and (3) all to be true, the antecedent of (1) must be false. That is, it must not be the case that it is possible for T1 to originate from B.

Similar considerations would show that T1 could not have originated from my non-A acorn or indeed from any thing whatsoever besides A. Indeed, similar considerations could also be used to attempt to establish origin essentialism for other organisms besides trees, for other natural objects besides organisms, and for artifacts.

This form of argument is also available to generate kinds of essentialism besides origin essentialism. The general argument structure is the following.* One can argue that, on the assumption that x is the F, being the F is essential to x, $-one is willing to maintain each of the claims:

(1) If it is possible that x exists without being the F, then it is also possible that x exists without being the F and something besides x is the F.

(2) If x is the F, then in any possible situation if y is the F then y = x.

This kind of argument has been put forth as establishing that each set contains its members e~sentially.~ Further, the widely-discussed view that a natural

7. See Salmon, Ref.r.lce and Essence, p. 199. Each of these further cases, howevrr, would require specific qualification of and refinements in the above kind of argument. In particular, one would need to account for the fact that, in many c a m , we would allow that an object might have had a somewhat different origin, but not a completely different origin. For various views on this problem, see William R. Carter, Salmon on Artifact Origins and Lost Possibilities, Philosophuul Review, vol. xcii (N83), pp. 223-23 I ; Roderick Chisholm, Identity Through Possible Worlds: Some Questions, NONOUS, vol. i (1967), pp. 1-8; Robert Coburn, Individual Essences and Possible Worlds, in French, Uehling and Wettstein (eds.), Midwest studzes in Philosopb, vol. xi, pp. 165-183; Forbes, 7he Metaphysics of Moduli&, Ch. 7, and Worlds and States of Affairs: How Similar Can They Be?, in Kevin Mulligan (ed.), Language, Tmth and onto lo^ (Kluwer, 1992), pp. I18--132; Lewis, On he Pluralirj of Worlds, pp. 243- 248; Thomas J. McKay, Against Constitutional Sufficiency Principles, in French, Uehling and Wettstein (eds.), Mdwest Sludies in Philosophy, vol. xi, pp. 295-304; Quine, Worlds Away, Journal $Philosophy, vol. lxxiii (1976), pp. 859-863; Salmon, Rtjkme and Essence, pp. 229- 252, Fregean Theory and the Four Worlds Paradox: A Reply to David Over, Philosophical Books, vol. xxv (1984), pp. 7-11, Impossible Worlds, Anahsir, vol. xliv (1984), pp. 114-117, Modal Paradox: Parts and Counterparts, Points and Counterpoints in French, Uehling and Wettstein (eds.), Mdwest Studks in Philosophy, vol. xi, pp. 75-120, and The Logic of What Might Have Been, Philosophuul &zim, vol. xcviii (1989), pp. 3-34.

8. See Van Cleve, Why a Set Contains Its Members Essentially, pp. 595-596; and Yabloh review of Forbes, pp. 335-336.

9. Forbes, Ihe Mefuphyics of Moduli&, Ch. 5; van Cleve, Why a Set Contains Its Members Essentially.

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kind (such as water, gold, or cats) possesses its physical structure essentially can also be reached by this type of argument.

Lets return to the argument concerning T 1. This argument is undeniably very significant because, as Yablo points out in a related context, it brings out hidden connections between superficially independent de re modal claimsnl-viz. between the claim of sufficiency and the claim of necessity. Even so, we can still wonder whether this argument allays Quinean doubts about a principled basis for treating some properties as essential to TI and others as not. We can see right away that it does not. This is because the argument for essentiality of origin assumes (2)) the claim that being an oak tree that originates from A is sufficient for being T1. As we saw, this assumption is tantamount to the assumption that certain properties such as spatial location, time of existence, etc. are non-essential to T1. Thus a certain property is classed as essential only by virtue of the fact that we have classed certain other properties as non-essential. But for a Quinean who is concerned about the legitimacy of classing properties as essential or as non-essential, such an assumption of non-essentiality is precisely the kind of claim whose legitimacy is doubtfii. Thus, by assuming (2), the above essentialist argument does not really address the Quinean concerns.12 Certainly (2) is a very strong intuitive claim but for one like Quine, who would demand a stronger basis than mere intuition to rest modal claims on, an assertion of such an intuition is not enough to jus@ (2) and hence not enough to j u s q the above argument for origin essentialism. By itself the argument does not go far enough.

Forbes, however, attempts to go further. In an important line of thought, he attempts to offer a justification for claims such as (2) (and hence for origin essentialism as well) that stems from the concept of identity. The conceptual truths about the identity relation that Forbes has in mind are:

(5) for any truth of the form: the object x satisfjmg condition F at world (or time) u is the same object as the objecty satisfying condition G at world (time) u

there must be intrinsic features of x at u and y at u in virtue of which that truth obtains

and

(6) for any truth of the form the object x satisfying condition F at world (or time) u is a different object from the objecty satisfjmg condition G at world (time) u

10. For essentialism about natural kinds, see Kripke, Naming and NecesiQ, pp. 116-140; and Hilary Putnam, The Meaning of Meaning , in his Philosophical Papers ZZ: Mind, Longuagc and halip, (Cambridge University Press, 1975), pp. 215-271. For some doubts about such essentialism, see Forbes, 17u Mehp/phs ofMoh&, Ch. 8; Putnam, Is Water Necessarily H20?, in his Rcalirm with a Human Fact (Harvard University Press, 1990), pp. 54-79; and Helen Steward, Identity Statements and the Necessary A Posteriori, Journal ofPhilosop/p, vol lxxxvii (1990), pp. 385-398.

11. Review of Forbes, p. 337. 12. See Salmon, Referee and Essmce; and Yablo, review of Forbes, p. 337.

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there must be intrinsic features of x at u and y at u in virtue of which that truth obta in~ . ~

Less formally, the principle is: for each instance of identity or failure of identity, there must be facts in virtue of which that instance obtains.* (6), the principle of the intrinsic grounding of diversity, is more directly relevant to the argument for origin essentialism, so I will focus on that. Forbes illustrates the plausibility of this principle by means of examples, one of which is this:

Consider the supposition that things could have been exactly as they are except that the steel tower in Paris opposite the Palais du Chaillot is different from the one actually there. To make sense of this supposition, it is not permitted to imagine that the tower is made of different metal from the metal which actually constitutes it, or that it has a different design, or designer, or history. The on& respect in which the imagined situation is to differ from the actual world is in the identity of the tower. The extent to which such a difference seems unintelligible is some measure of the plausibility of the view that transworld differences must be gr0~nded. l~

It is not immediately clear what Forbes means by intrinsic in (6), but the way in which he would invoke (6) to justfi (2) is clear. For (2) to be false, there must be a possible situation in which an oak tree that results from A is not T1, even though, in the actual situation, T1 is indeed the oak tree that results from A. Call the counterfactual oak tree that results from A T2 (cf. w3 described earlier). T2 # T1, but what can ground this non-identity? We need to find a difference between T2 and T1 (as it is in the actual world) that explains or grounds their non-identity. As we stipulated, they do not differ in origin. Perhaps they differ in location and, forat least some of their existence, in material constitution. Such differences are genuine, but, Forbes would say, extrinsic and so incapable of grounding the diversity in this case. Forbes would make the same claim for any other differences between the trees which share the same origin. He would, therefore, conclude that T2 = T1 after all and he would thus just+ (2), the claim that Tls actual origin is sufficient for being T 1.

As I said, it is not immediately clear what Forbes means by intrinsic. In particular, while the spatial location of a tree is, arguably, extrinsic, it seems more intuitive to regard material composition as intrinsic.16 Yet Forbes must regard material constitution as extrinsic. He goes some distance toward clarlfylng and justlfyrng his distinction between intrinsic and extrinsic, but in order to challenge (6) it is not necessary to explore this distinction further.

13. Forbes, In Defense of Absolute Essentialism, pp. 6-7. I have added numbers and changed

14. Forbes, ih Me&p&cs ofMo&l@, p. 130. 15. ih Mc&p/ysks ofModali& p. 128. 16. As Forbes himself notes (In Defense of Absolute Essentialism, p. 10). 17. In Defense of Absolute Essentialism, pp. 9-14.

some of the lettering.

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This is because there are very plausible counterexamples to (6), cases in which two things differ only in terms of what Forbes clearly regards as extrinsic properties.

Forbes himself raises the challenge by considering an example from Robert Adams:

[Clonsider a world in which there are two qualitatively indiscernible iron globes which have always and will always exist; that is all there is to w. But neither globe is essentially immortal, there are no restrictions on the times at which either globe could cease to exist . . . Thus there are worlds u and u just like w, except that in u one of the globes ceases to exist at a time t . . . while in u it is the other globe which ceases to exist then.18

Lets focus on w and on one of the other two worlds, u. w has two globes, A and B. u has two globes, A and B. In w, the globes are both eternal. In u, A is eternal, but B ceases to exist at, say, tl. Lets say that A = A and B = B. Thus u is a world in which B ceases to exist, but A does not. Since A # B and A = A, it follows that A # B. What grounds the transworld non- identity between A and B and the transworld identity between A and A? Forbes describes Adamss response as follows: [Alny feature we might appeal to as sufficing for the identity of A with A also holds between A and B. If this is correct, then, according to Forbes, the transworld identity and transworld non-identity in this case would be ungrounded.20 This would be a counterexample to (6).

To respond to this challenge, Forbes develops what he calls the branching conception of possible worlds, according to which

[wle can explain the facts about transworld identity in terms of identity through time. That is, one thinks of w as a course of events and of u and u as courses of events branching from w at the time tl when one globe ceases to exist in u and the other in u. Thus the transworld identities are explained by trans-temporal identities across the branch-point at t 1. Before tl, the very same course of events constitutes w, u, and v, and if we trace back in u from some point after tl into w, and trace back in u from some point after ti into w, we arrive at different globes; so the transworld difference between the u-globe and the u-globe is explained by the intraworld numerical difference of the globes in w together with the branching conception of the worlds.*

The idea seems to be this. u and w each contain numerically the same events up to, but not including time tl. From that point on, u consists of a separate

18. Ihc Me&zp/ysics of ModalzQ, p. 147; Adams example appears in Robert Adams, Primitive

19. IhcMetup/ysia OfModalzty, p. 150; I have, for clarity, employed my labels for the globes. 20. Adams speaks of primitive transworld identity and non-identity. Forbes takes Adams term

primitive to mean the same as Forbes ungrounded in this context (ne Metup/ysia of ModaliQ, p. 150), but this is not so clear.

Thisness and Primitive Identity, Journal gPhihsop/y, vol. lxxvi (1979), pp. 5-26.

2 1 . Ihc Metuphysics OfModali&, p. 150.

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course of events, one in which B' (i.e. B) ceases to exist at tl and A' (Le. A) continues to exist forever. The transworld diversity between A' and B is grounded simply in the transtemporal diversity within u between A' at t2 (a time after tl) and B at to (a time before tl).

This is a sophisticated line of thought, but to begin to challenge it, we can ask what difference grounds the transtemporal non-identity between A' at t2 and B at to? This non-identity, l i e all non-identities, would for Forbes require grounding. Forbes's answer, as suggested in the passage quoted above, is that A' at t2 is spatiotemporally continuous with A at to, whereas B at to is not spatiotemporally continuous with A at to. Instead, B at to is, of course, spatiotemporally continuous with B at to.

This account of the transtemporal non-identity of A' at t2 and B at depends crucially on the claim that A at to # B at to, for i f A at to were identical with B at then, it seems, by being spatiotemporally continuous with A at to, A' at t2 would also be spatiotemporally continuous with B at to. But Forbes explicitly denies that there is such continuity.

To summarise the argument so far: given the branching conception of possible worlds, Forbes grounds the non-identity of B and A' in the transtemporal non-identity of A' at t2 and B at to. This non-identity in turn is, at least in part, grounded in the non-identity of A at to and B at to. (This is diversity at a time, instead of transtemporal diversity.) But now the inevitable question arises: what grounds the non-identity of A at to and B at to? To answer this, one might appeal to the fact that A at to and B at to occupy different spatial locations. But, as we have seen, Forbes holds klausibly) that location is an extrinsic property, so this difference could not, for him, ground this non-identity. Perhaps the non-identity is grounded in the fact that the globes are made of two different quantities of matter. This might be seen as an intrinsic difference, but since the two quantities themselves are not identical, we would still need to find some intrinsic grounds of non-identity.

Let's try a different tack. Perhaps the diversity at a time between A and B is grounded in some transtemporal difference between A and B. This, however, will not work because, as we have just seen, the transtemporal differences in this case seem to be grounded in diversity at a time. Thus, on pain of circularity, we cannot appeal to transtemporal differences to ground the diversity at a time.

Similarly, Forbes cannot appeal to transworld or modal differences between A and B because, given his branching conception of possible worlds, such differences in this case are grounded in transtemporal differences and, ultimately, in the non-identity at a time of A and B. Thus again, for Forbes, it would be circular to ground the non-identity of A at to and B at to in transworld differences that are themselves grounded in that diversity at a time.

I can see no other way available to Forbes for grounding the diversity here and so I conclude that if Forbes invokes the branching conception of possible worlds to block Adams's argument for ungrounded transworld non-identities, he must accept cases of ungrounded intraworld diversity at a time. Although in the examples he provides to elucidate (6), Forbes focusses on transtemporal and transworld non-identity, (6) clearly entails that intraworld diversity at a

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time must also be grounded. Thus it seems that by avoiding one kind of counterexample to (6), Forbes is forced to embrace another. At the very least, then, we can say that Forbes has not offered a convincing case for (6).22

Perhaps a fd-back position is available. Perhaps Forbes can grant that there are cases of ungrounded intraworld diversity at a time, but still maintain that it is a conceptual truth that transworld diversity must be grounded. This more limited conceptual truth might be all Forbes needs for his argument for various forms of essentialism. Such a position may be consistent, but it seems troubliigly ad hoc. It is not clear why one kind of diversity should permit ungroundedness, while another does not allow for this. Certainly Forbes does not provide the materials for a justification for treating intraworld diversity at a time differently from transworld diversity. Without such a justification, the fall-back position would be entirely unmotivated.

Since a defence of (6), or at least of the grounding of transworld non- identity, is crucial to Forbess attempt to provide a principled basis for distinguishing between the necessary and contingent features of a thing and since Forbess defence has failed, it appears that Forbes does not provide this basis. It seems, then, that the kind of argument philosophers use to attempt to establish so many different essentialist claims has not been made immune to Quinean doubts about essentialism.

In 1968, before the heyday of essentialism inaugurated by Kripkes Naming and Necess$v, Richard Cartwright lamented the inability to resolve very many debates over the essentiality or accidentality of a given property. He concluded that

The existence of such cases, even in such large number, does not show that there is simply no distinction between essential and accidental attributes of an object. But it does show that the distinction is a good deal less clear than essentialists are wont to suppose.23

At least some of the challenges raised in this paper show, I believe, that, despite some very significant and groundbreaking work in the intervening quarter-century, Cartmights assessment is still correct.24 YALE UNIVERSITY MICHAEL DELLA ROCCA

22. For other criticisms of the branching conception of possible worlds, see Eugene Mills, Forbes Branching Conception of Possible Worlds, Anabsb, vol. l i (1991), pp. 48-50 and Yablo, review of Forbes. Salmon also rejects (6), though for reasons different from mine (Modal Paradox: Parts and Counterparts, Points and Counterpoints, in French, Uehling and Wettstein (eds.), Midwest Studies in Philosofly, vol. xi, pp. 75-120, appendix). For some responses by Forbes, see Worlds and States of Affairs: How Similar Can They Be?.

23. Richard Cartwright, Some Remarks on Essentialism, Journal ofPhiLosofhy, vol. lxv (1968), p. 626.

24. I am indebted to Teresa Robertson for very helpful discussions. My research was supported by a Morse Fellowship from Yale University.

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