subjective character of experience
Dualism
(philosophy of mind)
Functionalism
Hallucinations in the sane
Inverted spectrum
Mary's Room
Multiverse
Philosophical zombies
Philosophy of mind
Philosophy of perception
Physicalism
Pragmatism
Qualia
Synesthesia
The map is not the territory
Vertiginous question
https://en.wikipedia.org/wiki/Subjective_character_of_experience