What is Materialism?...

Most academic philosophers these days will tell you, without hesitation, that they are materialists. Materialism asserts that everything is or can be explained in relation to matter. This would be straightforward enough if we had a clear and stable idea of matter. But do we? Unfortunately, we don’t. There have been big changes since Descartes introduced his version of the mind/body problem in the 17th century. Descartes argued that the essence of matter is extension, or to put it another way, that what makes something material is having a shape at some particular position in space. Mass and energy don’t enter his account at all. After a number of important intermediate stages, we have arrived at a picture that takes mass and energy to be central, that makes shape unnecessary, and makes position in space problematic. Since Einstein, many physicists have regarded matter as a ‘lumpy’ form of energy. And quantum physics, with its Uncertainty Principle and probability waves, severs any necessary connection between being material and having some particular shape at some definite location. A materialist influenced by Cartesian physics offers us a very different picture of the world than a materialist influenced by quantum mechanics. The point is that the laws of physics (or, rather, our versions of them) are open to change. This means that our current concepts of matter (mass and energy) may change as well. If physics imposed logical constraints on these concepts — if it in some way limited their meaning or content — the problem might be solved. Materialism would then be the view that nothing exists which falls outside those constraints. But there are no such constraints. Or, rather, what seem to constrain physicists at one time are abandoned in another. After Einstein, no physicist thought that matter required a position in absolute space (as the Newtonians did). After quantum mechanics, few physicists thought that matter must be deterministic (as Einstein did). Now some physicists are seriously suggesting that matter can move backwards in time (as almost no one previously believed). The laws of physics get stranger every day and the only thing certain about the future of physics is that it will be decided by physicists. The physics of the future will not be bound by the physics of the present and certainly not by its metaphysics. As always, the physics of the future will let the philosophical chips fall where they may.
Perhaps we could say that matter is whatever physicists finally decide it is. But this reduces materialism to a blank check to be filled in when physics finally closes its book. To advocate materialism is now simply to pledge allegiance to physics’ final words (if any). Materialism is no longer a metaphysical doctrine. It is now the epistemological position that the methods of physics are such that they will finally map the structure of the universe.
Thus far we’ve been trying to understand what materialism asserts by looking for a clear and stable concept of matter. Maybe this is the wrong place to look. We might get further by thinking about all those spooky, ephemeral and esoteric things that materialism denies.
What are these things? Over the years, the targets have expanded. The main target of 17th century materialism was Descartes’ mental substance. Eighteenth and 19th century materialism was more ambitious, attacking both the supernatural in general (e.g., ghosts and magic), and religion in particular (e.g., immortal souls and divine intervention). The main targets of 20th century materialism expanded still further to include consciousness. These targets are very different but they have one important thing in common. In one way or another, they all challenge the idea that science is capable of producing a complete causal account of the universe. That is, they all claim that something outside the system of nature, as represented by science, either can have causal impact on the natural world, and/or can explain what we are and what will become of us. Let’s call the former ‘interventionism’ and the latter ‘exemptionism’.
The commitment to interventionism and exemptionism are obvious in the case of supernatural and religious phenomena. Gods, ghosts, witches and magicians intervene in the physical world by summoning forces and energy unknown to physics. Neither can immortal souls can be understood in terms described by science. The case of consciousness is less obvious but also strong. Despite nearly fifty years of concerted effort, states of consciousness have resisted all attempts at physical description. The difficulty isn’t hard to understand. The sensation of warmth, the taste of coffee, the sound of my voice in my head, have no quantifiable mass or energy and no actual location in physical space (we can’t open my head and find my headache). It is easy to think that they may be caused by the brain, but it is hard to think that they are the very same thing as what causes them. But if they are not identical, if experiences (as such) have causal power, they intervene in the material world just as gods and ghosts do. If a sensation of pain, considered just as such, just as an experience, can cause me to jump and shout, the laws of physics do not by themselves explain my jumping and shouting. That is why 20th century materialism takes consciousness to be a problem — especially the idea that conscious states can be causes of anything. Where does this leave us? We tried to understand what materialism asserts by understanding what matter is. After all was said and done, we were left with the epistemological doctrine that matter is whatever physicists finally say it is. This appeared to rob materialism of all content as a metaphysical doctrine. So instead we tried to understand it in relation to what it denies. But our efforts have taken us nearly full circle. The only common features of the processes and entities that materialists have denied is that they are interventionist or exemptionist. That is, they challenge the view that physics can provide a complete picture of the world and our place in it. So our second attempt to understand what materialism asserts leads us to nearly the same place as our first. Materialism is just the epistemological view that the methods of physics can provide us with a complete account of how things are.
© Michael Philips 2003
Michael Philips is a professor of philosophy at Portland State University in Portland, Oregon. In his spare time he is a photographer and performance artist.