Professor James, we see, has just told us that there are ever so many occasions upon which a particular true idea, such as that 2 + 2= 4, _would_ not be useful--when, on the contrary, it would be positively in the way. And this seems to be indisputably clear. But is not something else almost equally clear? Is it not almost equally clear that cases, such as he says _would_ not be useful, do sometimes actually happen? Is it not clear that we do actually sometimes have true ideas, at times when they are not useful, but are positively in the way? It seems to me to be perfectly clear that this does sometimes occur; and not sometimes only, but very commonly. The cases in which true ideas occur at times when they are useful, are, perhaps, far _more_ numerous; but, if we look at men in general, the cases in which true ideas occur, at times when they are not useful, do surely make up positively a very large number. Is it not the case that men do sometimes dwell on their faults and blemishes, when it is _not_ useful for them to do so? when they would much better be thinking of something else? Is it not the case that they are often unable to get their minds away from a true idea, when it is harmful for them to dwell on it? Still more commonly, does it not happen that they waste their time in acquiring pieces of information which are no use to them, though perhaps very useful to other people? All this seems to me to be undeniable--just as undeniable as what Professor James himself has said; and, if this is so, then, in one sense of the words, it is plainly not true that all, or nearly all, our true ideas are useful. _In one sense of the words._ For if I have the idea that 2+2=4 on one day, and then have it again the next, I may certainly, in a sense, call the idea I have on one day _one_ idea, and the idea I have on the next _another._ I have had two ideas that 2+2=4, and not one only. Or if two different persons both think that I have faults, there have been two ideas of this truth and not one only. And in asking whether _all_ our true ideas are useful, we might mean to ask whether _both_ of these ideas were useful and not merely whether one of them was. In this sense, then, it is plainly not true that _all_ our true ideas are useful. It is not true, that is, that every true idea is useful, _whenever it occurs._