 All reasoning must start from immediately evident principles if an infinite regress is to be avoided. This is as true in the realm of practical reason as it is in the realm of speculative reason. Once such principles have been grasped and assented to, more specific conclusions can be deduced. How are these principles grasped? In the domain of speculative reason, they are apprehended by the innate disposition that Aquinas calls intellectus—“intuitive reason” or “understanding”—and that Aristotle called nous. The objects of this habit are such self-evident propositions as that “every whole is greater than its part” and that “things equal to one and the same are equal to one another” (Summa theologica I-II, q 94, a. 2, corp.). Once their terms are known, the intellect immediately grasps the truth of such propositions since they are analytic in nature. The corresponding habit in the domain of practical reason, on the other hand, is synderesis: a property of the soul which can never be lost, which never errs, and whose objects are the first principles of the natural law (De veritate 16.1, corp.). A good description of how Aquinas understands synderesis is Hoffmann’s, who calls it an “infallible moral awareness” (Hoffmann 2012: 255). Like understanding, synderesis is innate: