"we call that natural which is produced by an agent to which the patient is naturally subject, even if what is produced is not conformed to the nature of the patient. . . ."
Thomas Aquinas, Commentary on the Epistle to the Romans, cap. 11, lect. 3, no. 910 (trans. Stroubant de Saint-Éloy, p. 404), as quoted by Jean-Miguel Garrigues, "Les prérogatives inaliénables du peuple juif selon saint Thomas commentant saint Paul à propos de La promesse par le Cardinal J.-M. Lustiger," Revue thomiste 103, no. 1 (2003): 156.