Jung wrote Part 1, "Approaching the Unconscious," of the book in English. The last year of his life was devoted almost entirely to this book, and when he died in June 1961, his own section was complete (he finished it, in fact, only some 10 days before his final illness) and his colleagues' chapters had all been approved by him in draft... The chapter that bears his name is his work and (apart from some fairly extensive editing to improve its intelligibility to the general reader) nobody else's. It was written, incidentally, in English. The remaining chapters were written by the various authors to Jung's direction and under his supervision.