Note 81:2 — Chapter II

["It is very common to confuse infallibility with certitude, but the two words stand for things quite distinct from each other. I remember for certain what I did yesterday, but still my memory is not infallible. I am quite clear that two and two makes four, but I often make mistakes in long addition sums. I have no doubt whatever that John or Richard is my true friend; but I have before now trusted those who failed me, and I may do so again before I die. I am quite certain that Victoria is our sovereign, and not her father, the Duke of Kent, without any claim myself to the gift of infallibility, as I may do a virtuous action, without being impeccable. I may be certain that the Church is infallible, while I am myself a fallible mortal; otherwise I cannot be certain that the Supreme Being is infallible, unless I am infallible myself. Certitude is directed to one or other definite concrete proposition. I am certain of propositions one, two, three, four, or five, one by one, each by itself. I can be certain of one of them, without being certain of the rest: that I am certain of the first makes it neither likely nor unlikely that I am certain of the second: but, were I infallible, then I should be certain, not only of one of them, but of all."—Essay on Assent, ch. vii. sect. 2.]