In this collection of essays, scholars examine the activity of knowing in late antiquity by focusing on thirteen major concepts from the intellectual, social, political, and cultural history of the period. They ask two questions about each of these concepts: what did late ancient people know about them, and how was that knowledge expressed in the actions that people undertook? Late Ancient Knowing integrates intellectual history and other forms of history by looking at the way that historical thought-worlds both shaped individual human lives and were shaped, in turn, by the actions that individual people took to live in those thought-worlds. Each chapter treats its main concept as a problem of both knowledge and practice or behavior. The result is a richly imagined description of how people of this time understood and navigated their world, from travel through the countryside and encounters with demons, to philosophical medicine and the etiquette of imperial courts.