This is a collection of essays on Aquinas and Wittgenstein. It is inspired by, and dedicated to the memory of Victor Preller, whose interpretations of these figures helped to prepare the ground for recent discussions of religious language, knowledge of God, the role of grace in human life, and the ethical significance of virtue. This book's main purpose is to advance our understanding of the issues on which texts like "Summa Theologiae" and the "Philosophical Investigations" have a bearing.