The divide between dualism and physicalism is a driving philosophical question in the discussion of the nature of mind and body. While dualists argue that the mind is an immaterial substance that transcends extension, physicalists believe that everything is physical or supervenes on the physical. A common form of physicalism is set forth in the type-identity thesis, which asserts that every type of mental state is identical to a type of physical state. The token-identity thesis is another, much narrower form which only equates an individual thought to an individual brain state. Physicalism comes to mean that there is nothing in the world that is not physical. Even mental states can be given purely empirical explanations. Frank Jackson objected …show more content…
Lewis holds that when Mary is released from the room, she does not gain any propositional knowledge, just knowledge how, or new abilities such as recognizing and remembering colors. Therefore, Mary does not discover anything about the qualities of color that she was not previously aware of. There is a physical separation between “knowledge that” and “knowledge how” and Mary gained another mechanism to understand color but does not actually know more about color. Therefore, physicalism is not threatened as it seems as though when she was in her room, her complete physical knowledge gave her a complete factual knowledge of what existed. However, a possible response to physicalists is that by experiencing color, Mary does gain factual, propositional knowledge about the experiences of others. In the case of red, she “knows that” red looks a certain way in comparison to other colors or “knows that” it has certain effects on her mental states, which she could not determine simply from knowing all of the physical facts about red. Additionally, Mary learned the qualitative features of other beings’ experiences of red that her physical, quantitative knowledge could never have afforded her. She did not know the non-physical facts about other beings’ experiences while she was in the room, as qualia cannot be physically modeled. The mere fact that Mary’s knowledge increases disproves the physicalist objection. Lewis fails to discount Jackson’s knowledge