The knowledge argument is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" and extended in "What Mary Didn't Know".
In philosophy and certain models of psychology, qualia are claimed to be individual instances of subjective, conscious experience.
A thought experiment considers some hypothesis, theory, or principle for the purpose of thinking through its consequences.
Frank Jackson - The Knowledge Argument - Mary's Room - Mary the Super-Scientist by Galen Orwell
The experiment is intended to argue against physicalism—the view that the universe, including all that is mental, is entirely physical.
In philosophy, physicalism is the ontological thesis that "everything is physical", that there is "nothing over and above" the physical, or that everything supervenes on the physical.
Mary's Room: A philosophical thought experiment - Eleanor Nelsen by TED-Ed
The debate that emerged following its publication became the subject of an edited volume—There's Something About Mary —which includes replies from such philosophers as Daniel Dennett, David Lewis, and Paul Churchland.
Daniel Clement Dennett III is an American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relate to evolutionary biology and cognitive science.
Paul Montgomery Churchland is a Canadian philosopher known for his studies in neurophilosophy and the philosophy of mind.