Alchemy's Own Version of the Problem

Property dualism has a notable premodern echo in alchemical matter theory, where a single physical substance, a metal or a compound, was often described as bearing both an ordinary physical nature and a further, non-reducible spiritual or subtle property, the very thing an operation like the alchemical purification was meant to refine and reveal without changing the substance's basic physical stuff; the echo is structural rather than historical descent, since the modern philosophical debate over qualia and the hard problem is a distinct, twentieth century conversation and not a direct outgrowth of alchemical theory. Within contemporary philosophy, property dualism is contested from both directions: physicalists argue Chalmers's hard problem is a conceptual confusion rather than a real explanatory gap, pointing out that plenty of scientific identities, water and H2O, heat and molecular motion, also once seemed to leave an unexplained further question that later dissolved once the science matured, while substance dualists argue property dualism does not go far enough, since a property with genuinely non-physical character sitting on a wholly physical substance is, on their reading, already most of the way to positing a second kind of stuff in all but name.