Inverted spectrumThe inverted spectrum is the hypothetical concept, pertaining to the philosophy of color, of two people sharing their color vocabulary and discriminations, although the colors one sees—one's qualia—are systematically different from the colors the other person sees. The concept dates back to John Locke. It invites us to imagine that we wake up one morning, and find that for some unknown reason all the colors in the world have been inverted, i.e. swapped to the hue on the opposite side of a color wheel, the complementary color.
Knowledge argumentThe knowledge argument (also known as Mary's Room or Mary the super-scientist) is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" (1982) and extended in "What Mary Didn't Know" (1986). The experiment describes Mary, a scientist who exists in a black-and-white world where she has extensive access to physical descriptions of color, but no actual perceptual experience of color. Mary has learned everything there is to learn about color, but she has never actually experienced it for herself.
Philosophy of mindPhilosophy of mind is a branch of philosophy that studies the ontology and nature of the mind and its relationship with the body. The mind–body problem is a paradigmatic issue in philosophy of mind, although a number of other issues are addressed, such as the hard problem of consciousness and the nature of particular mental states. Aspects of the mind that are studied include mental events, mental functions, mental properties, consciousness and its neural correlates, the ontology of the mind, the nature of cognition and of thought, and the relationship of the mind to the body.
Philosophical zombieA philosophical zombie (or "p-zombie") is a being in a thought experiment in philosophy of mind that is physically identical to a normal person but does not have conscious experience. For example, if a philosophical zombie were poked with a sharp object, it would not feel any pain, but it would behave exactly the way any conscious human would. Philosophical zombie arguments are used against forms of physicalism and in defense of the "hard problem of consciousness", which is the problem of accounting in physical terms for subjective, intrinsic, first-person, what-it's-like-ness experiences.
