Islamic philosopher Suhrawardi, one of the most important representatives of esoteric thought in the Middle Ages, established the Ishraqiyya, one of the two most important schools of Islamic philosophy, and studied the idea of nur in metaphysics. Leibniz, one of the most important philosophers of seventeenth-century Europe, argued that monads are the "ultimate units of existence in nature." This book studies the ideas, works, and impact of these philosophers first individually, then, in the third part of the book, in comparative perspective.