For 10 points, name these things, nonexistent examples of which include grue and bleen.
Core beliefs about one of these things including explanation and unity are introduced by Mark Johnston, who identifies this as a cluster concept. Descartes believed that perceiving these things was the same as perceiving something "to whose nature we are ignorant but which produces...sensation." A brilliant scientist who has never personally experienced this concept is introduced to them in Frank (*) Jackson's thought experiment about "Mary's Room." Two of these things are defined relative to time by Nelson Goodman's "new riddle of induction." A specific one of these concepts was imagined without existing by David Hume, who speculated on a "missing shade" of one of these. For 10 points, name these things, nonexistent examples of which include grue and bleen.
Core beliefs about one of these things including explanation and unity are introduced by Mark Johnston, who identifies this as a cluster concept.
colors