William Blake is best known and admired for Songs of Innocence and Experience. The same year as he completed it, he also published the earliest in his series of so-called ‘prophetic books’ that explore creation. Etched in double columns in imitation of the Bible, The First Book of Urizen (1794) is about the creation of earth, the first female, her son and his near sacrifice and what humankind lost when separated forever from Eternity. It tells of horrendous pain and disillusionment. Ever since the 1970s, critical interest in the work has been dominated by new historicist approaches that relate its interactions to events in the outer world of Blake's time. This article explores them as an expression of an autonomous process unfolding in his inner world. Its objective is to show not only how Jungian theory helps to identify and follow its concerns and intrinsic logic, but also how Blake's work broadens our understanding of the nature of unconscious processes.