Mieke Mosmuller provides an introduction in this book to the essence of the integral vision of the American writer Ken Wilber. Wilber is the author of more than twenty books that are read worldwide and brings together people from all over the world for integral spirituality. This book also includes an introduction to the spirituality of the West, which is European spirituality: esoteric Christianity, Rosicrucianism, and anthroposophy. This spirituality leads to a subtle, differentiated esoteric spiritual science. The two directions prove to be antitheses, and a synthesis seems impossible. Integral spirituality is unable to integrate the highly differentiated spiritual science of Rudolf Steiner. Mieke Mosmuller (Amsterdam, 1951) is a physician and has written 21 books in this field.