Hossein Jorjani First publication: 2026 – 06 – 30 The alchemists’ belief in the fixed “kinds” of metals drew upon the Platonic–Aristotelian tradition of essential forms, according to which each natural substance possessed a defining essence that determined its identity. The repeated failure to transmute one metal into another was taken by many as confirmationContinue reading “Excursus 012 – On Transmutability”