These four propositions are what I propose first to consider. He does mean to assert them, at least. Very likely he wishes to assert something more even than these. He does, in fact, suggest that he means to assert, in addition, that these properties of "verifiability" and "utility" are the _only_ properties (beside that of being properly _called_ "true") which belong to all our true ideas and to none but true ideas. But this obviously cannot be true, unless all these four propositions are true. And therefore we may as well consider them first. First, then, can we verify all our true ideas? I wish only to point out the plainest and most obvious reasons why I think it is doubtful whether we can. We are very often in doubt as to whether we did or did not do a certain thing in the past. We may have the idea that we did, and also the idea that we did not; and we may wish to find out which idea is the true one. Very often, indeed, I may believe very strongly, that I did do a certain thing; and somebody else, who has equally good reason to know, may believe equally strongly that I did not. For instance, I may have written a letter, and may believe that I used certain words in it. But my correspondent may believe that I did not. Can we always verify either of these ideas? Certainly sometimes we can. The letter may be produced, and prove that I did use the words in question. And I shall then have verified my idea. Or it may prove that I did not use them. And then we shall have verified my correspondent's idea. But, suppose the letter has been destroyed; suppose there is no copy of it, nor any trustworthy record of what was said in it; suppose there is no other witness as to what I said in it, beside myself and my correspondent? Can we then always verify which of our ideas is the true one? I think it is very doubtful whether we can _nearly_ always. Certainly we may often try to discover any possible means of verification, and be quite unable, for a time at least, to discover any. Such cases, in which we are unable, for a time at least, to verify either of two contradictory ideas, occur very commonly indeed. Let us take an even more trivial instance than the last. Bad whist-players often do not notice at all carefully which cards they have among the lower cards in a suit. At the end of a hand they cannot be certain whether they had or had not the seven of diamonds, or the five of spades. And, after the cards have been shuffled, a dispute will sometimes arise as to whether a particular player had the seven of diamonds or not. His partner may think that he had, and he himself may think that he had not. Both may be uncertain, and the memory of both, on such a point, may be well known to be untrustworthy. And, moreover, neither of the other players may be able to remember any better. Is it always possible to verify which of these ideas is the true one? Either the player did or did not have the seven of diamonds. This much is certain. One person thinks