The Diamond Approach has been developed and taught over the last twenty-five years by Hameed Ali (known chiefly by his pen name, A. H. Almaas), who is widely recognized as a leader in the integration of spirituality and psychology. This is the first book to introduce the complete spectrum of his teachings to a general audience.
A great book on understanding the deeper nature of self.
I thought it explained soul, spirit, ego and self really well.
It also helped in understanding all the differing views on soul and ego in various religious thought. ie. Gnostic, Buddhism, Sufism, Tao, Hindu, as well as resolving conflicts among and within them.