I’m a physicalist when it comes to human persons. I believe, in other words, that we are wholly physical objects. I don’t believe there are non-physical souls in the natural world. So I don’t believe that we are or have such non-physical souls as parts. I believe we are through-and-through physical. The physical stuff that I believe wholly composes us is chock-full of surprising potentialities, such as the potential to produce the wine of consciousness from the spectacularly complex network of one hundred billion nerve cells and their several hundred trillion synaptic connections in the wet-ware of the human brain. Even in a world overflowing with natural wonders—consider the marsupial wolf and the carnivorous plant, for example—it is a particular wonder that the natural world should contain conscious, self-conscious, personal, moral beings like ourselves. But it does! And while, to me, the “why” of our consciousness seems to fit most easily within a theistic understanding of the universe, the “how” of our consciousness seems increasingly to yield to naturalistic explanation.
Let me be clear. I do not reject dualism on account of any kind of philosophical or other kind of argument. In fact, I find many arguments against dualism—philosophical and otherwise—to be pretty weak specimens. I’m what a friend calls an antecedent materialist. In other words, I come to the discussion assuming I am a physical object, since that is what I have always seemed to myself to be for as long as I can remember. A non-physical soul doesn’t explain anything about consciousness that cannot be explained without it, and it is furthermore a wholly unnecessary hypothesis for many religious doctrines, despite intuitions to the contrary by many religious believers. For example, belief in an afterlife, belief in the peculiarly Christian idea of the incarnation of Christ, as well as the belief that we human beings bear the image of God—none requires belief in a non-physical soul in order to be made sense of. So until I am confronted with some knock-down, drag-out argument to the contrary, or until I am presented with some phenomena that cannot be accounted for in naturalistic terms or, yet again, until I have something resembling a conversion experience that forces me to renounce my physicalism, I'm sticking with it.
To go a bit further, let’s consider several theological doctrines that seem to cut against a physicalist conception of human personhood. These constitute perhaps the three most common objections Christian physicalists receive to their physicalism. After I address these objections, I will say a little more about the content of my own physicalist conception of human persons, The Constitution View. Perhaps in a future post I can say a little bit about the science of consciousness itself and address some of the most common objections to physicalism based on that mysterious phenomenon.
Theological Objections to Physicalism about Humans
The Incarnation of Christ
The doctrine of the incarnation of Christ is a central tenet of Christianity, and it may seem that the doctrine is inconsistent with a physicalist conception of human personhood. Yet I believe a physicalist view of human persons—like my own—actually makes better sense of the incarnation than does dualism. Let me explain.
The putative problem for the physicalist is this: if God (or the second person of the Trinity in particular) is essentially a non-physical being, then how could such a being become purely physical without losing an essential property? And if the second person of the Trinity loses an essential property, then wouldn’t he not simply cease to be fully God but simply cease to exist? (An essential property is a property a thing has and can’t lack without ceasing to exist. For example, my dog has the property of being a canine. He can’t lose that property without ceasing to exist—he is essentially a canine.)
Well, according to the Chalcedonian formulation, the incarnate Christ is one Person with two natures, a fully divine nature (that of the Second Person of the Trinity) and a fully human nature (that of Jesus from Nazareth). The Constitution View I hold divides things just where one would expect—between the human nature and the divine nature of the single person. And keep in mind, by the way, that the person of Christ is not human; he is divine, being the second person of the Trinity. But this one person, in the incarnation, had two natures--human and divine. In this understanding of the dual natures, Christ is wholly non-physical in his divine nature and wholly physical in his human nature. Now consider the somewhat-awkward cleavage Substance Dualists must offer. According to Substance Dualism, Christ is wholly non-physical in his divine nature and partly physical and partly non-physical in his human nature. Not especially elegant. To my mind, far from being unable to accommodate the doctrine of the incarnation, my physicalist view of human persons is actually better able to explain the doctrine than is dualism.
Notice that if what I said above is true, the way this objection is often put contains an important mistake in assuming that the second person of the Trinity ceased to be something he was apart from the incarnation. Indeed, the second person of the Trinity did not become purely physical (or even partly physical!). The second person of the Trinity did not give up non-physicality in the incarnation. Remember: one person (Divine and non-physical) with not one but (in the incarnation) two natures—one non-physical, the other physical. How can that be? I don’t have the slightest idea; but, the mystery of the incarnation is not explained away by any account, be it dualist or physicalist.
The Imago Dei
Now, what of the imago Dei or image of God? If it’s true that we human persons are wholly physical beings—as any version of physicalism must claim—then what does it now mean to say that we have been created in God’s image? Doesn’t having been created in the image of God just mean having a non-physical soul and the features of intellect, will and emotion that characterize soul? I do not believe that our having been created in the image of God means that we are non-physical as God is non-physical. What then does it mean?
Well, there are many ways of understanding the claim that we human beings image God. One might mean that we image God when we care for Creation and contribute to the terrestrial flourishing of the Created order. This, after all, is what the Bible means when it speaks of our having been given “dominion”. We are God’s vice-regents, as it were. To have dominion is to care for others, including non-human “others” like oceans and streams, octopus and salamander; in other words to have dominion is tend to the well being of all the earth. Second, one might mean that we image God when we live in loving relation to other human beings and invest ourselves in their flourishing and well being. For we are essentially persons-in-relation. Since God is a Trinity, it is not surprising that we should image God in virtue of our essentially social nature. The tenor of the relation between the three persons of the trinity is one of a harmonious and free exchange of love and joy. So engaging in acts of mercy, hospitality, love, kindness, etc. is to act like God. In fact, we image God when we image Jesus, who welcomed the outcast, fed the hungry, clothed the naked, hated evil and delighted in doing the work of the Father. Finally, one might claim that we image God in our suffering. God is love. To love is to open oneself up to suffering. And suffering love is God-love.
Now of course none of these ways that I have mentioned that we image God rules out the possibility that we are wholly or partly non-physical beings; but it doesn’t imply it either. The fact that we have been created in the image of God is perfectly compatible with the claim that we are wholly physical beings. Indeed, there is nothing in the doctrine of the imago Dei, rightly understood, that entails a dualist view of human nature.
But even if neither the doctrine of the incarnation nor the doctrine of humanity as reflecting the imago Dei require that we be at least partially non-physical beings, what about the issue of life after death? I’ll address that third challenge to a Christian physicalism tomorrow.