1. Materialism (only brain states exist)
2. Functionalism (software/hardware analogy of mind). Hilary Putnam used to be a functionalist.
3. Eliminative Materialism (brain states only with no emotions, beliefs or desires)
4. Biological Naturalism (consciousness arises from neurobiological processes)
5. Absolute Idealism (ideas constitute the fabric of reality)
6. Subjective Idealism (only ideas, minds and not matter--God makes sure that things are perceptible)
7. Occasionalism (God causes our thoughts and bodily motions to coincide: the deity is the only cause of our actions)
8. Substance Dualism (res extensa and res cogitans: Descartes says he is the latter rather than the former)
⃰Substance dualism allows for the possibility of disembodied existence as a thinking thing.
Granted, there seems to be a difference between physical and mental properties (warmth and feelings of warmth).
The mind-body problem thus arises. It revolves around causal interaction (hammer hits thumb, I feel pain or enough beer goes down my throat and I feel euphoric). How can something mental exert causal force on a physical entity or vice versa?