the base material of alchemy, in which lay the possibility of gold, was called Saturn, and this base material, as well as having a concrete existence, was also considered to be the alchemist himself.
Greene's programmatic argument: Saturn as alchemical prima materia identifies the planet with the psyche's own raw, unworked substance, making self-transformation inseparable from Saturnian engagement.
, Saturn: A New Look at an Old Devil, 1976thesis