Philosophical Studies

by G. E. Moore

(4) That all those of our ideas, which are useful, are true.

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 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.

It seems to me, then, that we very often have true ideas which we cannot verify; true ideas, which, in all probability, no man ever will be able to verify. And, so far, I have given only comparatively trivial instances. But it is plain that, in the same sense, historians are very frequently occupied with true ideas, which it is doubtful whether they can verify. One historian thinks that a certain event took place, and another that it did not; and both may admit that they cannot verify their idea. Subsequent historians may, no doubt, sometimes be able to verify one or the other. New evidence may be discovered or men may learn to make a better use of evidence already in existence. But is it certain that this will always happen? Is it certain that every question, about which historians have doubted, will some day be able to be settled by verification of one or the other hypothesis? Surely the probability is that in the case of an immense number of events, with regard to which we should like to know whether they happened or not, it never will be possible for any man to verify either the one hypothesis or the other. Yet it may be certain that either the events in question did happen or did not. Here, therefore, again, we have a large number of ideas—cases where many men doubt whether a thing did happen or did not, and have therefore the idea both of its having happened and of its not having happened—with regard to which it is certain that half of them are true, but where it seems highly doubtful whether any single one of them will ever be able to be verified. No doubt it is just possible that men will some day be able to verify every one of them. But surely it is very doubtful whether they will. And the theory against which I am protesting is the positive assertion that we can verify all our true ideas—that some one some day certainly will be able to verify every one of them. This theory, I urge, has all probability against it.

And so far I have been dealing only with ideas with regard to what happened in the past. These seem to me to be the cases which offer the most numerous and most certain exceptions to the rule that we can verify our true ideas. With regard to particular past events, either in their own lives or in those of other people, men very frequently have ideas, which it seems highly improbable that any man will ever be able to verify. And yet it is certain that a great many of these ideas are true, because in a great many cases we have both the idea that the event did happen and also the idea that it did not, when it is certain that one or other of these ideas is true. And these ideas with regard to past events would by themselves be sufficient for my purpose. If, as seems certain, there are many true ideas with regard to the past, which it is highly improbable that anyone will ever be able to verify, then, obviously, there is nothing in a true idea which makes it certain that we can verify it. But it is, I think, certainly not only in the case of ideas, with regard to the past, that it is doubtful whether we can verify all the true ideas we have. In the case of many generalisations dealing not only with the past but with the future, it is, I think, obviously doubtful whether we shall ever be able to verify all those which are true; although here, perhaps, in most cases, the probability that we shall not is not so great. But is it quite certain, that in all cases where scientific men have considered hypotheses, one or other of which must be true, either will ever be verified? It seems to be obviously doubtful. Take, for instance, the question whether our actual space is Euclidean or not. This is a case where the alternative has been considered; and where it is certain that, whatever be meant by "our actual space," it either is Euclidean or is not. It has been held, too, that the hypothesis that it is not Euclidean might, conceivably, be verified by observations. But it is doubtful whether it ever will be. And though it would be rash to say that no man ever will be able to verify either hypothesis; it is also rash to assert positively that we shall—that we certainly can verify the true hypotheses. There are, I believe, ever so many similar cases, where alternative hypotheses, one or other of which must be true, have occurred to men of science, and where yet it is very doubtful whether either ever will be verified. Or take, again, such ideas as the idea that there is a God, or the idea that we are immortal. Many men have had not only contradictory ideas, but contradictory beliefs, about these matters. And here we have cases where it is disputed whether these ideas have not actually been verified. But it seems to me doubtful whether they have been. And there is a view, which seems to me to deserve respect, that, in these matters, we never shall be able to verify the true hypothesis. Is it perfectly certain that this view is a false one? I do not say that it is true. I think it is quite possible that we shall some day be able to verify either the belief that we are immortal or the belief that we are not. But it seems to me doubtful whether we shall. And for this reason alone I should refuse to assent to the positive assertion that we certainly can verify all our true ideas.

When, therefore, Professor James tells us that "True ideas are those that we can assimilate, validate, corroborate and verify. False ideas are those that we cannot," there seems to be a serious objection to part of what these words imply. They imply that no idea of ours is true, unless we can verify it. They imply, therefore, that whenever a man wonders whether or not he had the seven of diamonds in the third hand at whist last night, neither of these ideas is true unless he can verify it. But it seems certain that in this, and an immense number of similar cases, one or other of the two ideas is true. Either, he did have the card in his hand or he did not. If anything is a fact, this is one. Either, therefore, Professor James' words imply the denial of this obvious fact, or else he implies that in all such cases we can verify one or other of the two ideas. But to this the objection is that, in any obvious sense of the words, it seems very doubtful whether we can. On the contrary it seems extremely probable that in a very large number of such cases no man ever will be able to verify either of the two ideas. There is, therefore, a serious objection to what Professor James' words imply. Whether he himself really means to assert these things which his words imply I do not know. Perhaps he would admit that, in this sense, we probably cannot verify nearly all our true ideas. All that I have wished to make plain is that there is, at least, an objection to what he says, whether to what he means or not. There is ample reason why we should refuse assent to the statement that none of our ideas are true, except those which we can verify.

But to another part of what he implies by the words quoted above, there is, I think, no serious objection. There is reason to object to the statement that we can verify all our true ideas; but to the statement that all ideas, which we can "assimilate, validate, corroborate and verify," are true, I see no serious objection. Here, I think, we might say simply that all ideas which we can verify are true. To this, which is the second of the four propositions, which I distinguished above ([p. 35]) as what Professor James seems to wish to assert, there is, I think, no serious objection, if we understand the word "verify" in its proper and natural sense. We may, no doubt, sometimes say that we have verified an idea or an hypothesis, when we have only obtained evidence which proves it to be probable, and does not prove it to be certain. And, if we use the word in this loose sense for incomplete verification, it is obviously the case that we may verify an idea which is not true. But it seems scarcely necessary to point this out. And where we really can completely verify an idea or an hypothesis, there, undoubtedly, the idea which we can verify is always true. The very meaning of the word "verify" is to find evidence which does really prove an idea to be true; and where an idea can be really proved to be true, it is of course, always true.

This is all I wish to say about Professor James' first two propositions, namely:—