Studies the original vocabulary of Frithjof Schuon, its relevance to comparative religion, and the status of metaphysical and theological terms in religion. This book explores the work of the religious philosopher Frithjof Schuon (1907–1998) by focusing on the way he develops his own expansive adaptations of traditional religious terms. As a leading proponent of perennial philosophical and religious thought, Schuon borrows widely from specific religious traditions, expanding the scope of traditional terminology-from upaya and yin-yang to 'quintessential Sufism' and 'vertical Trinity'-beyond their respective traditional definitions. This is one of Schuon's strengths as a thinker, but it can also be an obstacle to understanding his writings. This study develops the full implications of these key terms by first delving into their specific traditional denotations and, secondly, exploring their universal connotations in Schuon's universe of meaning. Such a task is particularly timely when