In November 1913, after his break with his one time colleague, Sigmund Freud, Jung began a personal exploration of the psyche. He called it his "confrontation with the unconscious", meaning he wilfully entered imaginative or "visionary" states of consciousness. The practice continued intensively from the end of 1913 until about 1917 and then abated by around 1923. Jung carefully recorded his journey of the imagination in six personal journals (referred to as the "Black Books", so named on account of their black covers). The notebooks provide a dated chronological ledger recording visions and dialogues with his soul."Carl Gustav Jung and The Red Book: Liber Novus" by Lance S. Owens and Stephan A. Hoeller Encyclopedia of Psychology and Religion, 2nd edition (New York, Heidelberg, Dordrecht, London: Springer Reference, 2014) https://www.academia.edu/6922901/C._G._Jung_and_the_Red_Book
