This essay examines Aquinas's discussions of hatred in Summa Theologica I-II, Q. 29 and II-II, Q. 34, in order to retrieve an account of what contemporary theorists of the emotions call its cognitive contents. In Aquinas's view, hatred is constituted as a passion by a narrative pattern that includes its intentional object, beliefs, perceptions of changes in bodily states, and motivated desires. This essay endorses Aquinas's broadly “cognitivist” account of passional hatred, in line with his way of treating passions in general. I suggest that Aquinas's account of hatred's arising out of attachment is compelling. However, I also argue that if Aquinas's treatment of hatred is to help us understand the phenomenon of hate, where classes of people are abominated for an identity they bear, and to avoid equating an oppressor's hatred with that of the oppressed for the oppressor, the cognitive pathway to hatred must be broader than through envy.