Iamblichus is the only Platonist philosopher whose philosophical letters have survived from the ancient world. These nineteen letters, which are translated into English here for the first time, address such topics as providence, fate, concord, marriage, bringing up children, ingratitude, music, and the cardinal virtues, with some letters addressed to students and others to prominent members of Syrian society and the imperial administration. The letters reflect the concerns of popular moral philosophy and illustrate the more public aspects of Iamblichus's philosophy. This volume provides a useful complement to Iamblichus: On the Mysteries, and On the Pythagorean Way of Life, both published by the Society of Biblical Literature, and will be of interest to students of late antiquity, of Neoplatonic philosophy, and of early Christianity.