To speak of philosophy (in its traditional sense) and mysticism and gnosis in their original sense which in Arabic and Persian are (ta~awwuf and 'iifiin) during the long span of Persian history, is to speak of tradition, I of continuity, of transcendent principles and of forms of wisdom of celestial origin. It is also to speak of two distinct spiritual worlds, the Mazdean and the Islamic, governed by different spiritual principles yet related in many ways because they issue from the same Divine Origin and also because of certain profound morphological resemblances between them. The question of the relation between the sapiental doctrines and methods of spiritual realization during these two phases of Persian history cannot be solved solely in the light of an historicism blind to the genius of both Mazdaism and Islam and of necessity impervious to the transcendent dimensions wherein resides the most profound relationship between them. To deny the transcendent and archetypal world as the origin of certain doctrines, forms, images and symbols which are manifested in both these worlds, is to overlook the main causal nexus between them. It is to search in the shadows, in the historical and purely horizontal relationships in time, for a reality which resides in the luminous world of the spirit above time, although it has manifested itself in different times and places.