Between 1913 and about 1930 Jung conducted on himself the experiment on which, he later said, all his work rested. In the crisis years after the break with Freud he deliberately induced waking fantasies, descended into them, and engaged their figures in dialogue: Elijah and Salome, the horned Philemon who taught him that the psyche's figures are autonomous, the dead who returned demanding answers. He recorded the visions in black notebooks, then transcribed and expanded them into a folio volume of his own calligraphy and painting, Liber Novus, the Red Book: gothic script, illuminated initials, mandalas and monsters in saturated colour, a medieval manuscript made by a twentieth century psychiatrist about his own interior. The method he distilled from the ordeal, active imagination, became a cornerstone of his therapy; the book itself he showed to almost no one. He worked on it privately, left it unfinished in mid sentence, and after his death in 1961 the family eventually placed it in a Zurich bank vault, where it lay for decades while scholars negotiated.
Publication came only in 2009, edited by Sonu Shamdasani, and the facsimile became an improbable bestseller. Its release rebalanced Jung's whole biography: the psychology of archetypes and individuation can now be read as the theoretical residue of a visionary practice Jung conducted first and theorised after, which is precisely the order of operations he always claimed.