A rich and immersive reinterpretation of the entire history of Western thought, this volume – the first in a major trilogy – explores the transmission and development of philosophical ideas from Plato and Aristotle to Jesus, Paul, Augustine and Gregory the Great. Christopher Celenza recalibrates philosophy's story not as abstract argumentation but rather as lived practice: one aimed at excavating wisdom and shaping life. Emphasizing the importance of textual tradition and elucidation across diverse contexts, the author shows how philosophical and religious ideas were transformed and readjusted over time. By focusing on the centrality of Christianity to Western thought, he reveals how ancient ideas were alchemized within religious frameworks, and how – across the centuries – ethical and intellectual traditions intersected to shape culture, memory, and the pursuit of sagacity. Ever attentive to ongoing conversations between past and present, this expansive intellectual history brings perspectives to the subject that are both nuanced and fresh.