The essays in this volume constitute a series of investigations into the limitations on thought and power as conceived by thinkers in the medieval West and they draw on material ranging from law to literature. The author deals with limits on the human desire for knowledge, the passion with which knowledge could legitimately be pursued, and the propriety of the knowledge sought, as well as the limits that might be tolerable and tolerated in the case of royal incapacity or misbehaviour. One particular focus is the work of Dante Alighieri, and these ideas are traced across a wide range of his thought. Chronologically the essays run from Augustine and the Gnostics through to Shakespeare.