Primary qualities: mind independent: the objective qualities about an object that remain the same. Secondary qualities: mind dependent, like taste and colour. There are many different versions of the view that the mind can be reduced to the brain or is the brain. Dualism: usually associated with religion, but can be a dualist without being religious. Substance dualism: the view that the mind and body are two distinct substances. Plato had a distinct form of dualism that attempted to explain how experiences and reality are connected. Think of the body as a house for the mind/soul. Believed truth is the ultimate truth, but we can never have that, we always have truth, because it"s obscured by our senses, only truth is objective. Believed world is divided into physical and nonphysical substances. For descartes, mental states are non-spatial experiences do not need to have an exact location.