This study investigates the historical and politico-philosophical origins of the rise of “tolerance” in the West. To this end, Abdelali delves into the ecclesiastical root of the word in the writings of St. Augustine and, later, Martin Luther. Further, he looks into the formation of the concept of tolerance in its various manifestations, such as the Edict of Nantes, the Pacification of Ghent, and the Declaration of Indulgence. These developments took place before “tolerance” came to take political and philosophical meanings, such as it does in John Locke’s Letter Concerning Toleration. It was in this secular formulation that tolerance was tied to a liberal school of thought that promoted the separation between religious and secular authorities; the “neutrality” of the state on religious beliefs; and the conceptualization of a neutral sphere not subject to the pressures of religion and belief—the sphere of liberty. Taking in contemporary, post-modern understandings of the concept of tolerance, the study also presents the ideas of communitarian political thinker Michael Walzer in contrast to the approach toward Liberalism represented by philosopher John Rawls.