Phenomenal consciousness in the context of "Robert Fludd"

In the philosophy of mind, the "hard problem" of consciousness is to explain why and how humans (and other organisms) have qualia, phenomenal consciousness, or subjective experience. It is contrasted with the "easy problems" of explaining why and how physical systems give a human being the ability to discriminate, to integrate information, and to perform behavioural functions such as watching, listening, speaking (including generating an utterance that appears to refer to personal behaviour or belief), and so forth. The easy problems are amenable to functional explanation—that is, explanations that are mechanistic or behavioural—since each physical system can be explained purely by reference to the "structure and dynamics" that underpin the phenomenon.

Proponents of the hard problem propose that it is categorically different from the easy problems since no mechanistic or behavioural explanation could explain the character of an experience, not even in principle. Even after all the relevant functional facts are explicated, they argue, there will still remain a further question: "why is the performance of these functions accompanied by experience?" To bolster their case, proponents of the hard problem frequently turn to various philosophical thought experiments, involving philosophical zombies, or inverted qualia, or the ineffability of colour experiences, or the unknowability of foreign states of consciousness, such as the experience of being a bat.

In philosophy of mind, a philosophical zombie (or "p-zombie") is a being in a thought experiment that is physically identical to a normal human being 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 react exactly the way any conscious human would. In other words, the being has full access consciousness, but no phenomenal consciousness.

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. Proponents of philosophical zombie arguments, such as the philosopher David Chalmers, argue that since a philosophical zombie is by definition physically identical to a conscious person, even its logical possibility refutes physicalism. This is because it establishes the existence of conscious experience as a further fact. Philosopher Daniel Stoljar points out that zombies need not be utterly without subjective states, and that even a subtle psychological difference between two hypothetically physically identical people, such as how coffee tastes to them, is enough to refute physicalism. Such arguments have been criticized by many philosophers. Some physicalists, such as Daniel Dennett, argue that philosophical zombies are logically incoherent and thus impossible, or that all humans are philosophical zombies; others, such as Christopher Hill, argue that philosophical zombies are coherent but metaphysically impossible.