What convergence is there between the journey of the ascetic Tibetan yogi Milarepa and that of the little-known great French mystic of the Seventeenth Century, Madame Guyon ? between Ramana Maharshi and the famous sufi Al-Hallaj ? What is the common denominator betweenthese extraordinary beings who, in such apparently dissimilar ways, climbed the rungs leading to the ultimate realization ? Is it not a question of the greatest importance, to conjecture about what is essential and what is of incidental value, about what is truly the core of a practice and what relates to a cultural context and epoch ?