1. Definitions and assumptions:
Physicalism (materialism): human beings are material objects (true; I assume that there is one immaterial thing God; all created things are material. Of course materialism taken as the view that only material things exist is false)
Reductionism: everything true about human beings can be expressed in the language of physics or of the special sciences (generally false: there are probably no psychological-physical type-identities)
Naturalism (human beings, their existence and characteristics, are subject to natural scientific explanation in essentially the same way as everything else in nature (true)
2. My project (The Material Image): materialism and naturalism as defined above are not merely consistent with Christian faith but probable in light of it
3. The two principal conceptual problems with physicalism:
a. freedom: if we are material things we are completely embedded in the quasi-deterministic order of nature, so how can we be free, morally responsible agents?
b. the hope of the resurrection: if we are functioning bodies how can we exist once they stop functioning and existing?
(other matters, including the nature of rationality and consciousness, and the nature of moral knowledge, become tractable - rather than being utterly mysterious - only on the physicalist assumption)
4. A requirement of minimal coherence: at the very least we hope to find that the blessed hope (and all other beliefs presupposed by faith in Christ) is not conceptually impossible (natural impossibility is no problem!)
5. A physicalist account of being a human being: a human person is a psychologically functioning human body (but not the set or sum of material constituents of that body)
6. A physicalist account of the resurrection: after a person dies, God will miraculously create a new human body that will be her.
7. The objection: "Anything existing after a thing is destroyed is at best an exact copy of it - but not identical to it. No matter what that future person God creates is like, it won't be you since the body that you are will be destroyed soon after you die, before that new body is created."
8. This is a problem of personal identity through time: how is it possible for a person existing at some future time, after this body that I am is destroyed, to be the same person as I am now? Body A at t is the same body as body B at t' just if relation R holds between A and B. What is that relation?
9. A physicalist account of personal identity through time: A stands in relation R to B just if: there's a relation of causal continuity between A to B. This asymmetric relation holds just if: B's properties are "nomologically dependent" on A having the properties it has: for a wide range of properties these counterfactuals hold (where A and B actually have F): If A had not had F then B would not have had F and (where neither A nor B actually have G): If A had had G then B would have had G.
10. A physicalist account of the resurrection: a person dies and shortly thereafter the dead body is destroyed. At some later time God creates a body C which is physically and psychologically very (but not exactly) similar to B. C stands in a relation of causal continuity to B just as B stands to A, but for different reasons: the causal continuity of A to B is due to the laws of nature, the causal continuity of C to A is due to God's intention and action: B's having property P causes God to create C with property P because of God's steadfast commitment to bringing it about that C has certain properties simply because B has them.
11. Second objection: if the relation of causal continuity is unique this is a contingent matter. It is possible that there is no unique causal continuant of B. Thus transitivity paradoxes: If God can create C then he can also create D which equally stands in relation R to B. This implies that C and D are the same person, i.e. one person is in two different places at the same time, having different experiences, etc. But this is absurd.
12. Transitivity paradoxes disarmed by a parity argument: resurrected identity not an essentially different problem than that of identity through time in this life: whatever the relation R is it is possible for it to obtain between A and B, A and C, and thus that B and C are the same person. This is an inevitable feature of physicalism.
13. The deeper problem: causal continuity is a matter of degree. It's not just that there can be ties; whether A is the same person as B might be ultimately indeterminate, not ascertainable because there simply is no fact of the matter. Further, any judgment about causal continuity involves picking out which properties are relevant and in what ways. There's no reason to think that these judgments are constrained by deep underlying facts, rather than by human interests. Our concept persondoes not 'cut nature at its joints.' (This is true because reductionism isn't.) Human persons (unlike the human bodies on which they supervene) are not natural kinds. If a kind F is not a natural kind then whether X is the same F as Y depends in part on how we find it useful to count and categorize, not on objective features of the universe.
14. This reveals our "ontological shallowness." We belong to the surface of the world; there's a point of view from which all things human disappear. The physicalist account of the world, i.e. the perspective of scientific naturalism, is profoundly unsettling for traditional humanistic views of ourselves; it forces us to see that "we are mere appearances, and the best explanation of nature will probably not employ the concept of the person" (Roger Scruton, Sexual Desire, p. 12). Yet this deflationary self-image comports deeply with the Christian confession that we are creatures, made, things, complex objects made out of other things. Scruton's claim is only the penultimate truth: the best explanation of nature employs the concept of the God who created a world for the purpose of bringing forth things like us, the material image of the Divine Person.
Thanks to Prof. Michael Andres for the opportunity to give this talk.