This book is a reprint of the dissertation that won the 2009 Prize of the Pontifical Academies. The analogy of names is not one of those topics that is important because it is a grand conclusion to intensive philosophical or theological research. Rather, analogy is important because it stands, explicitly or implicitly, at the very beginning of all work in philosophy and theology. For centuries, the thoughts of St. Thomas on analogy, which are found in texts scattered throughout his works, were considered to have been aptly grouped and articulated by Cardinal Cajetan. Most works on analogy in Aquinas since the time of Cajetan merely repeat what Cajetan said. This book approaches the question afresh, returning to the works of St. Thomas in order to find what he thought was the fundamental meaning of the word 'analogy.' Not only are several misconceptions about analogy cleared up, but a description is given of the way that God is first in our thoughts, as well as in reality.