This is the first complete English translation of the Jami al-hikmatayn, written in Persian, the final, and crowning, work of the great poet, philosopher, and Ismaili missionary Nasir-i Khusraw (1004-1077). Twin Wisdoms Reconciled was written at the request of the emir of Badakhshan 'Abu al-Ma'ali 'Ali ibn Asad' who was perplexed by the questions in a long philosophical ode written a century earlier by Abu al-Haytham Jurjani, an obscure Ismaili author. The ode consists of a series of some 90 questions on a wide range of subjects, from logic and metaphysics to medicine, cosmology, and physics, as well as esoteric Ismaili doctrine. Nasir-i Khusraw's text takes the form of a commentary on certain astutely selected lines. Twin Wisdoms Reconciled represents yet another example of the author's lifelong endeavour to transform Persian philosophical prose into a deft and nuanced instrument of expression. The work has not been as extensively studied as Nasir-i Khusraw's other major theological and philosophical treatises, all written in his final exile in Badakhshan, in part perhaps because of its textual difficulties. Twin Wisdoms Reconciled survives in a single manuscript of dubious accuracy in the Aya Sofya collection, Suleymaniyye Library, Istanbul. The present translation is based on the critical edition of the text produced by Henry Corbin and Mohammed Mo'in in 1953, but with frequent reference to the unique original manuscript. Twin Wisdoms Reconciled represents an endeavour to reconcile two apparently opposed forms of knowledge: the knowledge accorded by revelation and exegesis and the knowledge gained by reason. Seeing that "the bazaar of wisdom" stands empty because of the mutual incomprehension of traditional theologians and Aristotelian philosophers, Nasir-i Khusraw stepped boldly forward to reinvigorate that desolate marketplace. His final work, written in 1070, is thus a testimony as well as an exposition of his mature thought.