Dualism is the belief that there are separate physical and non-physical aspects of reality. This leads to the famous mind-body problem: if part of us is physical, and part non-physical, how do they interact? "Where" are they connected?

I don't claim to have the answer to that (although I do have a thought or two about it), but think it's still better than the other main alternatives: Idealism and Materialism/Physicalism/Scientism.

  • Idealism says that nothing actually physically exists. It's all some kind of illusion we (or maybe just you!) are experiencing. Maybe nothing except you exists. Repeatable experiments are basically just God or the universe pulling our (your?) legs.

  • Materialism (currently very popular among scientists) says that only the physical world exists. (Apparently the preferred term for this among philosophers has been Physicalism. And lately (2013) the word "Scientism" has come into broader use to descibe a philosophy that includes this as one element.) The problem with this is that people have no intrinsic worth, relative to very complex, useful machines. If you think you're in this category, but object to the proposition that computers will some day be exactly the same as people, I think you're confused.
  • So, I believe that if one is both a scientist and believes in any kind of spirituality, one is actually a dualist.

    For an entertaining general description of philosophy, see The Big Dummy's Guide to Theology, Philosophy, and Ethics.
    Sept. 2002: This link finally works again; I found its new home!