that he did, and another thinks he did not; and both, so soon as the question is raised, have before their minds both of these ideas--the idea that he did, and the idea that he did not. This also is certain. And it is certain that one or other of these two ideas is true. But can they always verify either of them? Sometimes, no doubt, they can, even after the cards have been shuffled. There may have been a fifth person present, overlooking the play, whose memory is perfectly trustworthy, and whose word may be taken as settling the point. Or the players may themselves be able, by recalling other incidents of play, to arrive at such a certainty as may be said to verify the one hypothesis or the other. But very often neither of these two things will occur. And, in such a case, is it always possible to verify the true idea? Perhaps, theoretically, it may be still possible. Theoretically, I suppose, the fact that one player, and not any of the other three, had the card in his hand, may have made some difference to the card, which _might_ be discovered by some possible method of scientific investigation. Perhaps some such difference may remain even after the same card has been repeatedly used in many subsequent games. But suppose the same question arises again, a week after the original game was played. Did you, or did you not, last week have the seven of diamonds in that particular hand? The question has not been settled in the meantime; and now, perhaps, the original pack of cards has been destroyed. Is it still possible to verify either idea? Theoretically, I suppose, it may be still possible. But even this, I think, is very doubtful. And surely it is plain that, humanly and practically speaking, it will often have become quite impossible to verify either idea. In all probability it never will be possible for any man to verify whether I had the card or not on this particular occasion. No doubt we are here speaking of an idea, which some man _could have_ verified at one time. But the hypothesis I am considering is the hypothesis that we never have a true idea, which we _can_ not verify; that is to say, which we cannot verify _after_ the idea has occurred. And with regard to this hypothesis, it seems to me quite plain that _very often indeed_ we have two ideas, one or other of which is certainly true; and yet that, in all probability, it is no longer possible and never will be possible for any man to verify either.