I'm a sceptical epistemological realist; and more vaguely, a transcendental idealist. Though I'm also a pragmatic Popperian empiricist.
Since all the information we have about objects comes through the senses there are limitations on what we can say about them. But certain consistencies occur. For instance objects are recognisable, and memorable. With reference to any particular object, people agree (more often than not) that there is an object, and also agree on its general characteristics, even though specifics may be disputed. If you could see me writing this you'd probably agree that I'm sitting at a desk, in a room, in a house, in a town, etc; or you'd be open to the charge of madness. If someone else sees an object and communicates to me about it in a way that suggests that they see the same object as I see, then I take that as evidence pointing towards the independence of the object from either of our minds. When everyone laughs at the same time in a movie then it suggests the movie is external to all of us. Explaining observations like these becomes very difficult if objects only exist in our minds.
The view that objects only exist when I observe them at best is egocentric. But consider - when I leave my room and go downstairs to make a cup of coffee, it seems nonsensical to me that my room and all of the hundreds of objects which fill it cease to be because I'm not there to see them. And what about when I blink? In that fraction of a second when I do not see the things, do they disappear? And do they then reappear when my eyes are open again? What happens to them during my blink? Trying to explain this is much more difficult, much more cumbersome, than assuming than that the objects simply exist. However I don't think we can say much about that existence, which is why I am a sceptical empirical realist.
It is my view that the Buddha was unconcerned with the nature of existence, or reality. That is to say he was not concerned with the nature of the objective pole of experience. This lack of concern with existence (and non-existence) is clear in, for instance, the Kaccānagotta Sutta, and strongly re-emphasised in Nāgārjuna's Mūlamadhyamakakārikā. The duality between subject and object is uncontentious in the Pāli Canon, it is simply a given. The conceptualisation of the problem of suffering, all of the analysis, and all of the practices, focus on the subjective side of experience. The nature of the object is simply irrelevant, it has to be there of course, but the arising of suffering is to do with our internal relationship to our perceptions, not with the objects of perception.
I've also said that I'm a transcendental realist, which in a way flows out of the previous paragraph. I must say I'm not a very sophisticated transcendental realist, and not very well versed in Kant or other philosophers of that ilk. Kant began with a problem. Hume had showed that a purely empirical approach to knowledge denied the possibility of metaphysical concepts like causality, time, and space. On the other hand empirical scientists, exemplified by Newton, had shown that we can say very definite things about causality, time, and space. Newton's well-known laws of motion are example. Kant's solution to this was to propose that the human mind interpreted sense experience in terms of inbuilt, or a-priori, categories of knowledge. The very usefulness of Newton's laws showed that a-priori categories had, to some extent, to reflect reality. Kant showed that the subject was involved in the creation of all knowledge, but that knowledge thereby created was valid. We can know useful things about the universe and how it works. Things are more or less as they appear to us.
In terms of my approach to Buddhism what this comes down to is, again, a focus on understanding the subjective side of experience, trying to understand the a-priori, what we bring to our interpretations of experience. This comes out of a study and practice of Buddhism, but in terms of relating it to the categories of Western philosophy this is as close as I've come. The fundamental problem is that we interpret experience in ways that cause us misery. Experience arises out of contact between objects and our sensory apparatus - but it is not the experience per se that is problematic, not the raw experience anyway. It what we make of experience, and how we relate to experience, the stories we tell ourselves about experience that cause us suffering. In other words it is not pleasure per se that is evil, only the pursuit of pleasure with the thought that it will make us happy. Hence the knowledge we need is knowledge of our relationship to experience; knowledge of the way we process experience into views and reactions. It is this kind of knowledge that will be liberating.
The last label I referred to was "pragmatic Popperian empiricist". Karl Popper was to some extent reacting against a trend in European thought which sought to evaluate all knowledge by the criteria of 'verifiability'. That is to say some philosophers were not prepared to accept knowledge as valid unless it could be verified. Sadly, although this philosophical position has long been superseded, it is more or less the popular view that science operates along these lines. But any living scientist will acknowledge the contribution of Karl Popper. At one time it was axiomatic that all Swans were white, because no European had ever seen a Swan that was any other colour. The statement "all swans are white" had become a standard in textbooks of logic even. However when Europeans got to Australia they discovered black swans. One can never anticipate when one might find a black swan which falsifies the statement that all swans are white. And this is the essence of Karl Popper's theory of knowledge, which informs my own understanding, and all of modern science. Facts and laws are only ever provisional because at any time a counter-example may disprove them. Theories might prove to be useful, but they can never be proved once and for all.
I said I'm also a pragmatist and this is because though they cannot be falsified, let alone proved, some forms of knowledge and some forms of practice are useful, or better helpful (I'm not a utilitarian). Some forms of knowledge which have been falsified on one level, even retain their usefulness on another. It is a fact that Newton's Laws remain useful in some contexts - say landing a human on the moon, or designing an aeroplane - even though observations have shown them to be inaccurate, for instance, when considering objects moving close to the speed of light. Then there is the placebo effect, the phenomena that we heal better, if we believe that we have had an effective treatment - even though it may be false to state that we have actually had an effective treatment, still we fair better than if we had no treatment at all. I argued this in the case of karma, which cannot be either verified or disproved, but is still useful as a view in helping to determine how we should behave. That is, I believe the theory of karma is morally helpful, even though it has doubtful truth value, if only in a provisional sense. (see Hierarchies of Values). Despite my definite preference for the rational, factual truth is not the only criteria that I apply when assessing the value of an idea. I may also form an opinion on the basis of helpfulness, or more aesthetic qualities such as elegance or beauty.
I don't feel entirely comfortable with this kind of discussion, or with these kinds of labels, I'm all too aware of the extent of my ignorance of Western philosophy. But when someone calls me a materialist because I'm educated in, and enthusiastic about, the scientific method, I need a way to respond which doesn't buy in to the simplistic duality being proposed: either one is a materialist, or a non-materialist. This simple opposition is not very helpful. People don't really hold views that are either one or the other, but have a far more sophisticated relationship to the objective pole of experience. One simply cannot be a practising Buddhist, as I have been for 16 years, and maintain a purely materialist view of the world. Clearly I do have a view about the material world, and I do think science can tell us far more about the material world than can Buddhism, but my focus is very much on the subjective, on the relationship to perception, on the nature of experience. Traditional Buddhist approaches to knowledge are rooted in pre-technological world-views that are frequently little better than superstition - the Buddha has a magical ability to know ultimate reality through super-powers - which just doesn't chime with my own experience of Buddhists and Buddhism. I see the European Enlightenment as a good thing (unlike some of my colleagues).
The other aspect of the criticism was that scientific investigation is reductionist. Reductionism by definition is the attempt to "explain a complex set of facts, entities, phenomena, or structures by another, simpler set" (the free dictionary). Which means of course that Buddhist doctrine is on the whole reductionist, because at its heart are explanations of phenomena in terms of short lists of mental states and events; and simplified models of dependent arising. By contrast some people try to explain phenomena in terms of more complex, often metaphysical or even mystical, ideas; they go against Occam and invent new entities to explain what they experience. What to call this kind of approach? Inflationist? The inflationist critique of science is that it tries to explain the unknown in terms of the known; whereas inflationists try to explain things in terms of the unknown, and the more mysterious the better. Apparently no one likes to admit that they simply don't know the cause of some experiences, nor the nature of them. If someone claims to remember a past life and I express doubt then I am, apparently, a materialist. But I don't see why an experience should be interpreted in terms of mysterious entities and processes as opposed to known entities and processes, if the truth is that we just don't know.
The charge is that experience is reduced only to that which can be measured. I would turn this around: it seems to me that inflationistists tend to project their subjectivity onto the world, and assign it an objective status which it does not deserve. There are many examples of inflationism stemming from interpretations of Indian religious ideas. Despite all evidence to the contrary people treat cakras, for instance, as really existent rather than symbolic or at best subjective; similarly they insist that the mysterious 'third eye' has some physical manifestation in the body (a past acquaintance assured me that it was connected to the pineal gland!) . I know many people who have seen or felt ghosts, because the house up the road (which is occupied by members of my order and community) is haunted. In fact it is supposedly one of the most haunted houses in the UK. I do not doubt that people have had uncanny, strange, unnerving, and inexplicable experiences. However I also do not necessarily accept that ghosts are the best explanation for those experiences. Some experiences do not have external objects, as anyone who has ever meditated, dreamed, taken psychedelic drugs, or gone mad will confirm. Actually anyone who ever thought, or remembered, or imagined anything is not (necessarily) working with external objects. A ghost certainly has more mystique, than a hallucination, but is it more likely? I'd have to say no. Plus at least half of the weird experiences are obviously caused by sleep paralysis. [See also today's xkcd cartoon]
So, am I a materialist? No. I'm a sceptical epistemological realist, a transcendental idealist, and a pragmatic Popperian empiricist (or something like that - actually I usually just say Buddhist). As such I don't have much to say about the nature of existence or reality (or any of that material stuff). Although I really enjoyed those Brian Cox documentaries and read Stephen Hawking, these days I'm mostly interested in the nature of experience. I do see an empirical approach to investigating it as the most useful; though I'm prepared to be pragmatic about what is helpful for that investigation. The main point is that I reject the dumbing down of religious discussions, especially in the area of the interaction between religion and science. If anything is dry and reductionist, and frankly boring, it is the idea that everyone interested in science is necessarily a materialist.
Next week [22 Oct 2010] I attempt to demolish the idea that Buddhism and Quantum Mechanics have anything in common. See Erwin Schrödinger Didn't Have a Cat.