 Scotus holds that we have “necessary certitude” about four kinds of knowledge. The first type is knowledge of self-evident propositions (propositions per se notae)—such as ‘a whole is greater than its parts’—as well as knowledge of propositions derived syllogistically from them. This type of knowledge amounts to necessary, analytic truths, in his view: once one knows the terms that enter into such a proposition, and once those terms are combined into the proposition, one cannot help but assent. Scotus’ second type of knowledge is knowledge of our own contingent acts, including such propositions as ‘I am awake’ and ‘I am alive’. Scotus follows Augustine in holding that such knowledge is immune to skeptical attack because even if the senses are deceived, once these terms are grasped, we can know the truth about them in such propositional contexts.