Argument from consciousness: mind and matter are ontologically distinct; consciousness is irreducible to physical processes (the hard problem of consciousness)

John explains that the argument from consciousness rests on the ontological distinction between mind and matter. You cannot reduce consciousness to physical processes — an alien who fully understood human physiology still could not know what it is like for a human to feel sad. This is called the "hard problem of consciousness." Since immaterial thoughts cannot be extended in time and space, they are a different kind of substance than the physical body. This raises the question: where does the non-physical come in? On naturalism, getting mind from matter is like getting something non-wood from a pile of wood.