Ibn Warraq on Islam and Reason

As Ibn Warraq sums up in his modern classic Why I Am Not a Muslim:

...orthodox Islam emerged victorious from the encounter with Greek philosophy. Islam rejected the idea that one could attain truth with unaided human reason and settled for the unreflective comforts of the putatively superior truth of divine revelation. Wherever one decides to place the date of this victory of orthodox Islam (perhaps in the ninth century with the conversion of al-Ashari, or in the eleventh century with the works of al-Ghazali), it has been, I believe, an unmitigated disaster for all Muslims, indeed all mankind.