I hazard a guess that this commentary on Aquinas’s question on homicide is the fi rst extended commentary written in about 400 years. Treatments of the question, and of Thomas’s ideas, are found in theology manuals down through the centuries. I mention some of these in my commentary. However, this book is a commentary in the sense in which de Vitoria’s lectures of the 1530s are commentaries, and this you don’t fi nd in the theology manuals. Vitoria ranges widely over many topics and considers dozens of arguments made by philosophers since Aquinas. He does not proceed exegetically, carefully weighing Aquinas’s words, but he sees himself as a defender of Thomas’s basic positions, not only Thomas’s commitment to capital punishment or his “extreme” formulation respecting self-defense, but also a signature thesis like intrinsicalism. As discussed in the sixth chapter, Carl Schmitt fi nds in de Vitoria a Thomist wrestling with, voicing, and developing a change in world consciousness. For him, de Vitoria’s originality is less the use of Roman law in a natural law treatise and rather that natural law is given a “planetary consciousness,” a new awareness, as de Vitoria wrestles with the implications of the New World. Nothing so grand, I assure you, is happening in my commentary.