Although the role of emotion in law has become a major field of scholarship, there has been very little attention paid to the role of emotion in constitutional theory. This Article seeks to fill that gap by providing an integrated account of the role of emotion within the individual, how emotion affects constitutional culture, and how constitutional culture, properly understood, should affect our evaluation of major constitutional theories. The Article begins by reconstructing one of the most important and influential accounts of emotion in the philosophical literature: that of Thomas Aquinas. Because Aquinas’s description of the nature of emotion accords with modern science and the insights of many law-and-emotion theorists, it provides a ...