3/30/2005

Body & Soul II

The idea that science captures everything, except the center of everyone’s universe, his own consciousness, makes a laughing-stock of its claim to present a plausible world view.
--Howard Robinson

The field of neuroscience cannot be successful in its ultimate aim of building a conscious, living machine if anything like Christianity is true. But what concrete boundaries does this place on future discoveries about the brain’s function? What properties of human souls (and minds in particular) cannot be modeled by a purely physical system?

One possibility is life itself. There’s good reason to think that the soul is the animating force, the life principle of the body (cf. Gen. 2, Ezekiel 37). Without a soul our bodies are lifeless because our soul is our life. If the soul is the life principle, then not only humans but also plants and animals have souls (though not, of course, immortal or conferring personhood, and much simpler than ours, especially in the case of plants). This idea is as old as Aristotle, and following him it has been the traditional Christian view as well. If this is true, then man cannot create life. Man’s creations may move, they may be very complicated, but they are not alive. It is certainly true that man is very good at manipulating life, but that is not the same thing. I am reminded of an episode of SeaQuest (the second season, when it got really weird) – the ship had been sent to the future to help save humanity or something. One of the future-humans remarks “we never learned what time was, but we learned how to manipulate it.” Modern biology gives me the same feeling about life: they don’t know what it is (though many think they do), but they are becoming increasingly adept at manipulating it. However, cause and effect are not nearly as explanatory as naturalists assume1. The fact that a new living organism emerges when two living entities (i.e., egg and sperm) are physically joined together does not mean that life is strictly a material phenomenon. The fact that we only see physical interactions when we look at the cell through a microscope does not mean that life is strictly a material phenomenon. The existence of the soul is perfectly consistent with all the scientific data. Moreland and Rae suggest in Body & Soul that there are certain physical conditions (i.e., fertilization of egg by sperm) which are invariably associated with the creation of a new soul – either by a direct act of God or by certain “soulish” capacities in the cell. The soul then guides the organism in the maturation process, using the (inherently inert) genetic material as a tool. In Aristotelean terms, the soul is the final cause of development. It provides teleology, purpose.

So, science can only mimic and manipulate life, not create it. And despite popular opinion, scientific observations have little to say one way or the other about the existence of the soul. But a more interesting question, to me at least, is the role of the soul or mind in cognition, intelligence, self-consciousness, etc. What in these activities is necessarily metaphysical?

One candidate is the self, the “I”, the first-person perspective. I’m not sure I could cite a specific Biblical reason for the existence of the immaterial self, but it’s such a basic concept I don’t think I need to. It is certainly true that the Bible assumes the existence of a spiritual identity capable of surviving the death of the body... maybe this is more or less the same thing. At any rate the existence of the self is not something that is likely to be controversial in the Christian community. However, if matter is all there is and the mind is just a combination of brain states, then the first-person statement “I feel pain in my right forefinger” is identical to the third-person statement “the brain located at (x,y) is in such-and-such a state. Emily told me that one of the professors at a philosophy program Bill Rowley was considering refuses to refer to himself in the first person for precisely this reason – he denies the existence of the first person perspective. This is the kind of thing one needs a PhD to believe.

Another candidate is human creativity. When God declares “Let us make man in Our own image”, virtually the only thing that has been revealed about Him at that point in Genesis is that He is a creator. That creativity was imparted to man as a part of God’s image, one of His highest gifts. The creative process is notoriously mysterious. Homer invokes the inspiration of the Muse, and anyone who has ever created something will recognize this as an apt metaphor – to an artist, it really does feel sometimes as if what he is producing is coming from somewhere else, bypassing his mind and flowing directly to his fingers, to such a degree that he may be surprised at what he’s produced. J.R.R. Tolkien had something of this experience in writing The Lord of the Rings. He mentions in one of his letters that he was as surprised as the reader when, at the beginning of the novel, Gandalf failed to visit Frodo as he had promised. Since creativity is a property that humanity (to some degree) shares with God, and God is not material, it seems reasonable to assume that human creative capacities are not material either.

None of this is likely to be convincing to a materialist – his philosophy has already caused him to regard most human intuitions as simply mistaken. But I’m not trying to convince a materialist, I’m trying to reason about what neuroscience can and cannot discover about the brain’s physical properties, given the truths of Christianity. So far the candidates for irreducibly metaphysical properties are: life, self-consciousness, and creativity. There are probably more (suggestions are, of course, welcome). Higher brain functions would be impossible to duplicate to the extent they depend on these metaphysical properties of the mind. For example, it is hard to imagine rational thought without a self to do the thinking; however certain parts of reasoning are extremely rule-based, and computers can easily be taught these rules.

While this provides a rough outline of the boundaries around what neuroscience can accomplish, it is a very wide boundary, and it says nothing about the degree to which a complex physical system could mimic the observable behavior of these properties. This, admittedly, has little to do with neuroscience because it involves approximating the brain’s behavior, not modeling it. Nevertheless, it’s an interesting question. That will be the topic of my next post.



1This deserves an entire post, but see Hume’s An Enquiry Concerning Human Understanding. Compare with Chesterton, Orthodoxy, ch. 4

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