Philosophy is a discipline that makes no observations, conducts no experiments, and needs no input from experience. It is an armchair subject, requiring only thought. Yet that thought can advance knowledge in unexpected directions, not only through the discovery of new facts but also by improving our understanding of what we already know. Philosophy can clarify our vision of the world and arm us with ways to interpret it.Of course, philosophy’s unified purpose hasn’t prevented the discipline from splintering into a number of warring camps. Departments all over the world are divided among analytical and continental schools, Heidegger, Hegel, and other major thinkers, challenging the growth of the discipline and obscuring its relevance and intent. Having spent decades teaching philosophy in American, Asian, African, and European universities, Michael Dummett has witnessed firsthand the fractured state of contemporary practice and the urgent need for reconciliation. Setting forth a proposal for renewal and reengagement, Dummett begins by describing the nature of philosophical inquiry as it has developed for centuries, especially its exceptional openness and perspective, which has, ironically, led to our present crisis. He discusses philosophy in relation to science, religion, morality, language, and meaning and suggests avenues for healing the discipline, potentially around a renewed investigation of the mind, language, and thought. Dummett’s popularity as a teacher and writer stems from his frankness and accessibility, and he brings these very qualities to a major intellectual intervention.