 These don’t sound right for real humans, as opposed to idealized, logically infallible agents. (C1): we know basic arithmetic truths like Peano’s postulates, and these entail (suppose) Goldbach’s Conjecture (Every even whole number larger than 2 is the sum of two primes); but we don’t know whether Goldbach’s Conjecture is true. (C2): “If \({\sim}{\sim}A\), then \(A\)” is (suppose) valid, but intuitionist logicians do not believe it. (C3): we can have, if implicitly, inconsistent beliefs.