A friend and former student recently asked me what to think about "monism." Is it compatible with Christianity? Are "monism" and "dualism" the only alternatives, or is there a third one?
I think we need to start by defining "monism" and thinking about just what the problems might be with it from a Christian perspective. And the best place to start for that is surely the very beginning--i.e., the doctrine of creation :)
There are three possible positions on creation from a broadly theist perspective:
1. God and matter coexist eternally, and God gives "form" to matter. This is the most clearly heretical, and the most clearly dualist. It is the version maintained by "dualist" versions of Hindu philosophy, by most of the ancient Greeks (including Plato, if I'm not mistaken!), by Mormons, and by modern process theologians. it is also, if you read purely from a historical point of view, the most likely interpretation of Genesis 1 (I think one can make a case for "bara" meaning "create out of nothing," but it's a case that really depends heavily on reading Scripture through later Christian tradition--which I think is the correct way to read, of course!) The problem with it from an orthodox Christian perspective is that if there are "two eternities" then God isn't the source of everything and thus one can say that there are two Gods. It's central to Christian piety to say that God is in fact the source of everything that exists. Which is, in a sense, a form of monism, whatever later distinctions we make.
2. Everything "emanates" from God. This I think is the position that can be called "monism." IN this view, it is true in some sense to say that everything is God. Ultimately God is the only reality and creation's distinction from God is not ultimate. This is the view of Vedanta philosophy--the version of Hindu philosophy best known in the West and probably most important within India as well, though that's harder for me to evaluate. It's also, of course, the view of modern "idealist" philosophers in the West, often influenced by Indian philosophy. And historically it was, as far as I can tell, the view of the Neo-Platonists (as opposed to Plato himself), though I may be wrong and they may still have been dualists with regard to matter. This is also considered unorthodox in the Christian tradition, and in fact most modern Christians would pounce on this as the most obviously heretical view--but in fact I think it's harder to explain just why this is wrong. More on this in a minute.
3. Creation out of nothing. This, of course, is the orthodox answer, clearly in the saddle by the time of Athanasius in the early fourth century. But it raises philosophical puzzles. Since "nothing" isn't a thing, how can you talk about something being "created out of" it? In the Summa Theologiae, Aquinas argues that the word "of" ("ex" in Latin) has two possible meanings:
a. It refers to order: that is, it means that first there was nothing, and then there was creation. (To make things more complicated, Aquinas thinks that this is a logical rather than necessarily temporal order.) Or
b. It is included under the negation found in the word "nothing." That is to say, it means "not created out of anything." In this sense, the phrase simply denies that there is any material cause of being taken as a whole. God is not the material cause (indeed, since for Aquinas God is pure form, God can't be the material cause of anything), but there is no eternal material cause either. This does not mean that there is no cause at all (as in a silly atheist article I ran into the other day, which claimed that "creation out of nothing" means that creation just pops randomly into being). In Aristotelian philosophy there are four causes: efficient, formal, material, and final. The universe taken as a whole has no material cause, and God is the cause in the other three senses: God's will is the efficient cause, God's glory is the final cause, and God's knowledge of Himself as capable of being imitated is the formal cause.
In other words, for Aquinas creation out of nothing means that God knows that finite imitations of His infinite goodness can exist, and sovereignly chooses to bring these imitations into existence. They exist only by participation in the being of God. Indeed, Aquinas uses the word "emanation" (which modern Christians tend to associate with the second view of creation and think of as "New Agey") repeatedly in describing how things come into existence.
So what is the real difference between the second and third views? I think there are two big differences:
1. In the orthodox Christian view, a real relationship between creatures and God is possible.The goal is not to lose our identity in God but to know God as the source of our being and become eternally more and more like God, while remaining always infinitely less than God. I don't know that I'm willing to say that this is impossible in the "creation out of God" view. There are forms of Hinduism which start from Vedanta principles but try to find room for a real relationship with God. I do not understand these philosophies well enough to analyze or evaluate them, but certainly the concept of "creation out of nothing" helps give shape to the idea of a relationship between us and God.
2. A clearer difference is that in the creation out of nothing view, it is possible for human beings to be eternally separated from God. Even here, though, I think a case can be made that the orthodox Christian view actually has elements of "emanationism," precisely because annihilation isn't seen as an option. Creation out of nothing would seem to imply that if separated from God we would cease to exist, and there are those who have maintained this position. But the mainstream, historic Christian view is that those created in God's image who choose to remain separated from God will in some sense remain in existence. It looks as if, then, in the Christian view the gift of life in God's image is irrevocable, and this is best explained by the idea that there is something "divine" within us which cannot simply cease to exist once God has created us (and yes, that raises a lot of debates about animals that I don't want to get into in this post!). Yet we don't say that if a person is damned, part of God is damned. In fact, God has no parts in the classic, historic view.
To summarize all of this . . . it looks very much as if the orthodox Christian view comes close to monism, while maintaining the possibility of real relationship between us and God and the possibility that we will not finally be united to God.
How does this affect our relationship with our own bodies, which is the concern behind the original question?
I'm going against N. T. Wright and the whole trend of modern (at least Protestant) theology when I say this, but I think that a neo-Platonic, panentheistic, modified emanationist view of the kind I've been articulating does best justice to the question of how we relate to our bodies.
In this view, as articulated by Aquinas, God knows Himself as imitable in a variety of ways, arranged in a hierarchy: Angels (pure spirit, but created by God)
Human beings (embodied creatures capable of abstract thought and free choice)
"Brute" animals (embodied creatures capable of moving around and of sensory responses to their environment, including basic mental activity but not reason or free choice)
Plants (embodied creatures capable of growing and receiving nourishment)
Inanimate things (bodies with no life at all)
In this way of thinking, each of these "ranks" as you go down shares in less of the being of God (this was traditionally called the "Great Chain of Being"). In this view, humans are "amphibians" (to use C. S. Lewis' vivid term). They have a rational soul which, as with other living things, serves as the form of their bodies. But unlike other animals, not to say plants, human beings can think and love.
There are all kinds of problems with Aquinas' articulation of this, both in terms of the philosophy of his own day and in terms of contemporary concerns. For one thing, what does it mean for there to be wholly immaterial beings that are still created and finite? Furthermore, if angels are seen as "pure intellect," then are our souls, when "liberated" from the body, essentially the same as angels? That would be the pure "Platonic" view attacked by most modern Christians, but Aquinas doesn't think this. He thinks, with Aristotle, that the soul is the form of the body. It would seem to follow that the soul can't exist without the body. Aquinas thinks it can, but that it isn't a full human person in that state. He believes that form is made individual by matter, which means both that angels aren't individual members of a species (each angel is its own species) and that disembodied human souls are only individuals because their bodies have somehow put a stamp on them.
In contemporary terms, the biggest objection to Aquinas' view tends to be his treatment of non-human animals. Are they really incapable of reason and choice? Aquinas' view certainly wasn't as extreme as that of, say, Descartes, who thought that animals were just machines. But it clearly has problems.
So why would I hold to some version of this as my starting point for thinking about the body? I think the key point in this traditional view is the great chain of being--that everything exists by participation according to its degree in the eternal, infinite Being of God. Mind and body are different simply because we can say with qualifications that God knows and wills, whereas we can't say that God (apart from the Incarnation) has a body. In other words, our intellect, memory, and will constitute that part of us that is most directly like God. This doesn't mean that our minds are our "real selves" and our bodies are temporary possessions, and it certainly doesn't mean that our bodies are bad. Creation is God's gracious decision to make things that reflect Himself while being distinct from Himself. Both our minds and our bodies do this, but in different ways and to radically different degrees. The best thought is thought that is heavily embedded in our bodiliness, and the best bodies are bodies that are shot through with knowledge and love. The goal--the mission we have been given by God with our very being--is to unify mind and body, not separate them. One of the reasons Christians have reacted against the traditional view is that it's always been shadowed by the ghost of Plato's Phaedo, whispering "the real job is to separate mind and body." That's where the Platonic heritage does need to be sharply critiqued and even rejected. The fundamental distinction to be made isn't between mind and body, but between Creator and creation. All the distinctions within creation are just variations on a theme: the many ways in which God's glory can be reflected in that which God has caused to exist.