ABSTRACT
So extensive is our experience of human fallibility that we have very good reason to expect that no book which makes a large number of statements will be totally free of error. The author does not, of course, know which of the statements are false, and she may have good reason to believe each of the statements in her book. In any case she is committed to each of them. So the chances are that she is already committed to at least one falsehood. If this is so, to add the statement in the preface is to add a truth, and thereby increase the number of truths she states. ‘He is always right’, goes the Spanish proverb, ‘who suspects he is always making mistakes’. Falsehood is unlikely to be avoided by omitting the preface. So we have a case where it is perfectly rational to commit oneself to each of a set of inconsistent beliefs, even though one knows they are jointly inconsistent and so cannot all be true. What the paradox shows is that we need to give up the claim that it is always irrational to believe statements that are mutually inconsistent.
