Editing Knowledge argument (section)

== Thought experiment ==
Mary is the second character put forward by Jackson in his article ''Epiphenomenal Qualia''. The other is a gifted person called "Fred" who "has better colour vision than anyone else on record"; specifically, Fred can see two different colours of red where ordinary colour vision only sees one.<ref name=epiph />{{rp|128}}

The thought experiment was originally proposed by Jackson as follows:

{{Quote frame|text=Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black and white room via a black and white television monitor. She specialises in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like 'red', 'blue', and so on...What will happen when Mary is released from her black and white room or is given a colour television monitor? Will she learn anything or not?|}}

There is disagreement about how to summarize the premises and conclusion of Jackson's argument in this thought experiment. Paul Churchland did as follows:

# Mary knows everything there is to know about brain states and their properties.
# It is not the case that Mary knows everything there is to know about sensations and their properties.
# Therefore, sensations and their properties are not the same (≠) as the brain states and their properties.

However, Jackson opposes it by saying that Churchland's formulation is not his intended argument. He especially objects to the first premise of Churchland's formulation: "The whole thrust of the knowledge argument is that Mary (before her release) does not know everything there is to know about brain states and their properties because she does not know about certain qualia associated with them. What is complete, according to the argument, is her knowledge of matters physical."<ref name=":3" /><ref name=":4" /> He suggests his preferred interpretation:

# Mary (before her release) knows everything physical there is to know about other people.
# Mary (before her release) does not know everything there is to know about other people (because she learns something about them on her release).
# Therefore, there are truths about other people (and herself) which escape the physicalist story.

Later on, Amy Kind proposes another summary for the argument:<ref name=":2" />

# While in the room, Mary has acquired all the physical facts there are about color sensations, including the sensation of seeing red.
# When Mary exits the Room and sees a ripe red tomato, she learns a new fact about the sensation of seeing red, namely its subjective character.
# Therefore, there are non-physical facts about color sensations. [From 1, 2]
# If there are non-physical facts about color sensations, then color sensations are non-physical events.
# Therefore, color sensations are non-physical events. [From 3, 4]
# If color sensations are non-physical events, then physicalism is false.
# Therefore, physicalism is false. [From 5, 6]