For Aquinas, enemyness is contingent evil added to nature, not an essential difference.

Evidence

Although Aquinas never directly defines the attributes of enmity, in this distinction, the being of the enemy is or not coextensive with his being a human being, with his nature. “Enemyness” can be contingent, the enemy may also be other than enemy, and therefore loving the enemy as enemy, insofar as he is enemy, is, again, perverse. Moreover, Aquinas explains, such love would have nothing to do with caritas, but would fall short of and even be opposed to caritas “because it means loving evil in another.” Such would be the quality of the enemy, then: It is what is evil in the other. Being the enemy is therefore not natural, nor does it signal an essential difference between the one who loves and the enemy. Rather, it appears to be an appended part, an evil part added to one’s nature. — Gil Anidjar, The Jew, the Arab, 180

Categorization

• DEFINE: Defines Aquinas’s ontological status of ‘the enemy’ as accidental evil appended to nature rather than essential difference — foundational to the book’s genealogy.