This volume gathers together the numerous essays by the Iranian metaphysician and ontologist, Seyyed Hossein Nasr, on Islamic philosophers and the intricate relationship between Persian culture and its philosophical schools. Brought together into a single volume for the first time, these essays span four decades of Nasr's prolific and learned scholarship on the development of Islamic philosophy, as well as the general history of Islam, and expound his belief that philosophy is not merely a rational but a sacred activity - a quest for the Eternal resulting from a longing within us all to return to our original, and true, selves.