Book excerpt: A groundbreaking and wide-ranging presentation of Plutarch’s ethics based on the cosmological foundation of his ethical thought Plutarch of Chaeronea (c. 45-120 CE) is the most prolific and influential moral philosopher in the Platonic tradition. This book is a fundamental reappraisal of Plutarch’s ethical thought. It shows how Plutarch based his ethics on his particular interpretation of Plato’s cosmology: our quest for the good life should start by considering the good cosmos in which we live. The practical consequences of this cosmological foundation permeate various domains of Greco-Roman life: the musician, the organiser of a drinking party, and the politician should all be guided by cosmology. After exploring these domains, this book offers in-depth interpretations of two works which can only be fully understood by paying attention to cosmological aspects: Dialogue on Love and On Tranquillity of Mind.