Online research in philosophy

In this note I revive a lingering (albeit dormant) account of rigid designation from the pages of Mind with the aim of laying it to rest. Why let a sleeping dog lie when you can put it down? André Gallois (1986) has proposed an account of rigid designators that allegedly squares with Saul Kripke’s (1980) characterisation of them as terms which designate the same object in all possible worlds, but on which, contra Kripke, identity sentences involving rigid designators may be merely contingently true. This suits Gallois, as he finds the notion of contingent identity coherent. Thus, the thrust of Gallois’ thesis is that his account of rigidity is preferable to Kripke’s because his accommodates a coherent metaphysical viewpoint, whereas Kripke’s doesn’t. Gallois has thwarted one unconvincing challenge (see Carter 1987; Gallois 1988) and his account, as yet, remains untainted. But not for long, I hope.1 Let us assume, for the sake of argument, that the notion of contingent identity is coherent, that, in other words, it makes—or can make—sense to say that certain (possible) objects are identical in one world but distinct in another. What I shall argue here is that Gallois’ account of rigidity would prevent us from expressing the contingent nonidentity of objects; if so, this is a significant failing of the account, for, as it will emerge, clearly Gallois is committed to the contingency of non-identity.

It may be that all that matters for the modalities, possibility and necessity, is the object named by the proper name, not which proper name names it. An influential defender of this view is Saul Kripke. Kripke’s defense is criticized in the paper.

In the first post World War II identity theories (e.g., Place 1956, Smart 1962), mind brain identities were held to be contingent. However, in work beginning in the late 1960's, Saul Kripke (1971, 1980) convinced the philosophical community that true identity statements involving names and natural kind terms are necessarily true and furthermore, that many such necessary identities can only be known a posteriori. Kripke also offered an explanation of the a posteriori nature of ordinary theoretical identities such as that water = H2O. We identify the kinds and substances involved in theoretical identities by certain of their contingent properties. What we discover when we discover a theoretical identity is the underlying nature of the kind that we identify by those contingent properties. Now, of course, it was being a posteriori, not being contingent, that mattered to the identity theorists anyway, so the necessity of identity is not, in itself, damaging to mind brain identity theories. However, Kripke also argued persuasively that the alleged mind brain identities could not be treated in the same way as ordinary theoretical identities. We "identify" pain by feeling it, and surely how it feels is an essential property of pain, not a contingent property. Thus, a mind body identity theory must provide a different explanation of why its identities are a posteriori. A new wave of materialists has appeared on the scene with a new strategy for explaining [1] the a posteriori nature of its alleged identities. The strategy is to locate the explanation for the a posteriori nature of mind body identities, not on the side of the world, but on the side of the mind -in different ways of thinking about or imagining, or in different concepts. Thus, on this new view, there is only one property—this brain process type, which is identical with this pain..

This paper analyses and criticizes S. Kripke's celebrated argument against materialist identity?theories. While criticisms of Kripke in the literature attack one or more of his premisses, an attempt is made here to show that Kripke's conclusion is unjustified even if his premisses are accepted. Kripke's premisses have sufficient independent plausibility to make this strategy interesting. Having stated Kripke's argument, it is pointed out that Kripke must assume that the contents of the Cartesian intuitions are clear and of a kind suited for the type of explanation he favours, while his own result concerning contents in epistemic contexts is precisely that this might not be so when objects or events we thought distinct happen to be identical. The point is that only by assuming that the identity?theory is false, can Kripke maintain that the Cartesian intuitions express contents which can be explained in his favoured way. But such an assumption is clearly illegitimate when the aim is to establish that the identity?theory is false. Kripke cannot conclude that the identity?theory is false because no explanation of epistemic possibilities is produced, since by his own standards no such explanation can be produced if the identity?theory is true.

Kripke's argument against the identity theory in the philosophy of mind runs as follows. Suppose some psychophysical identity statement S is true. Then S would seem to be contingent at least in the sense that S seems possibly false. And given that seeming contingency entails genuine contingency when it comes to such statements S is contingent. But S is necessary if true. So S is false. This entry considers responses to each of the three premises. It turns out that each response does not fully withstand scrutiny, and so Kripke's conclusion is hard to resist. Section 1 lays out Kripke's argument, and Sections 2 to 4 then discuss responses to each of the three premises respectively.

Abstract Thomas Polger has argued in favour of the mind?brain type?identity theory, the view that mental states or processes are type?identical to states of the central nervous system. Acknowledging that the type?materialist must respond to Kripke?s modal anti?materialist argument, Polger insists that Kripke?s argument rests on dubious assumptions concerning the identity conditions of brain states. In brief, Polger claims that one knows that x and y are non?identical when one knows the identity conditions for both x and y. Replace x and y with ?brain states? and ?sensations? and it follows that one can know that brain states and sensations are non?identical only if one knows the identity conditions for brain states. But according to Polger, we do not know the identity conditions for brain states. Hence, we should not be so confident that brain states and sensations are non?identical after all. But Polger?s account is terribly flawed. Ironically, if Polger?s scepticism is warranted, then Polger himself has no good reasons to be a type?materialist. But more importantly, Polger?s scepticism regarding the identity conditions of brain states is deeply defective. We do, I submit, understand the identity conditions of brain states. In the end, I submit, Kripke is safe from Polger.