We commonly assume that religion is simply part of a person's identity, a preference, or a choice. This is a result of the modern liberal rejection of all but empirical knowledge and the corresponding public rejection of metaphysics. This makes it impossible to make philosophically coherent arguments that humans have real moral duties. Yet, given persistent human diversity, questions of morality and justice, decisions about which power and authority are often called on to enforce, will only become more intractable to the extent that we are unable to identify a sure basis on which to decide them. To find such a basis, we must abandon the modern liberal prejudice against all non-empirical knowledge and reconsider how we could actually learn anything that is true from any of the different so-called religious traditions in our midst, which unanimously affirm that people have real moral duties, and if so, what we might learn. Since Islam represents one of the most significant, theologically and philosophically comprehensive alternatives to modem liberalism, I ask what we can learn from Islam that can be shown to be true in any way that could provide a sure basis for deliberating about the truth of different moral and ethical claims, without presupposing any particular kind of faith or belief. With a view to answering this question, I offer a comprehensive study of the political thought of Tariq Ramadan. Unlike many contemporary Muslim thinkers who try to make Islam appear fully compatible with modern liberalism, Ramadan critiques aspects of liberalism and seeks to enrich the West with direct reference to Islam. I argue that he articulates a radical and compelling philosophy of pluralism derived from his understanding of Islam that provides a clear criterion for determining the morality of any given moral claim. This criterion, I argue, is grounded in a claim about the nature of ultimate reality that can be shown to be true. Building on his work, I show how this is so, demonstrating how it is possible to take questions about ultimate truth and the relationship between truth and politics seriously, despite modern liberal claims to the contrary.