The perennial philosophy (Latin: philosophia perennis), also referred to as perennialism and perennial wisdom, is a school of thought in philosophy and spirituality that posits that the recurrence of common themes across world religions illuminates universal truths about the nature of reality, humanity, ethics, and consciousness. Some perennialists emphasize common themes in religious experiences and mystical traditions across time and cultures; others argue that religious traditions share a single metaphysical truth or origin from which all esoteric and exoteric knowledge and doctrine have developed.
Perennialism has its roots in the Renaissance-era interest in neo-Platonism and its idea of the One from which all existence emerges. Marsilio Ficino (1433–1499) sought to integrate Hermeticism with Greek and Christian thought, discerning a prisca theologia found in all ages. Giovanni Pico della Mirandola (1463–1494) suggested that truth could be found in many—rather than just Biblical and Aristotelian traditions. He proposed a harmony between the thought of Plato and Aristotle and saw aspects of the prisca theologia in Averroes (Ibn Rushd), the Quran, Kabbalah, and other sources. Agostino Steuco (1497–1548) coined the term philosophia perennis.