The Persian mind, having adjusted itself to the new Political environment, soon reasserts its innate freedom, and begins to retire from the field of: objectivity, in order that it may come back to itself and reflect upon the material achieved in its journey out of its own inwardness. With the study of Greek thought, the spirit which was almost lost in the concrete, begins to reflect and realise itself as the arbiter of truth. Subjectivity asserts itself, and endeavours to supplant all outward authority. Such a period, in the intellectual history of a people, must be the epoch of rationalism, scepticism, mysticism, heresy - forms in which the human mind, swayed by the growing force of subjectivity, rejects all external standards of truth. And so we find the epoch under consideration.
The period of Umayyad dominance is taken up, with the process of co-mingling and adjustment to new conditions of life; but with the rise of the Abbasid Dynasty and the study of Greek Philosophy, the pent-up intellectual force of Persia bursts out