The alchemists were fond of picturing their opus as a circulatory process, as a circular distillation or as the uroboros, the snake biting its own tail… the lapis, as prima materia, stands at the beginning of the process as well as at the end.
Jung identifies alchemical recursion as the structural heart of the opus, wherein the prima materia and the lapis are identical, making the process inherently self-returning and self-grounding.
, Aion: Researches into the Phenomenology of the Self, 1951thesis