It seems to me, then, that if we mean by an idea, not mere words, but the kind of idea which words express, any idea, which is true at one time when it occurs, _would_ be true at any time when it were to occur; and that this is so, even though it is an idea, which refers to facts which are mutable. My being in this room is a fact which is now, but which certainly has not been at every time and will not be at every time. And the words "I _am_ in this room," though they express a truth now, would not have expressed one if I had used them yesterday, and will not if I use them to-morrow. But if we consider the idea which these words _now_ express--namely, the idea of the connection of my being in this room with this particular time--it seems to me evident that anybody who had thought of that connection at any time in the past, would have been thinking truly, and that anybody who were to think of it at any time in the future would be thinking truly. This seems to me to be the sense in which truths are immutable--in which no idea can change from true to false. And I think Professor James means to deny of truths generally, if not of all truths, that they are immutable even in this sense. If he does not mean this there seems nothing left for him to mean, when he says that truths are mutable, except (1) that some _facts_ are mutable, and (2) that the same _words_ may be true at one time and false at another. And it seems to me impossible that he could speak as he does, if he meant _nothing more_ than these two things. I believe, therefore, that he is really thinking that ideas which have been once true (_ideas,_ and not merely words) do sometimes afterwards become false: that the very same idea is at one time true and at another false. But he certainly gives no instance which shows that this does ever occur. And how far does he mean his principle to carry him? Does he hold that this idea that Julius Caesar was murdered in the Senate-House, though true now, may, at some future time cease to be true, if it should be more profitable to the lives of future generations to believe that he died in his bed? Things like this are what his words seem to imply; and, even if he does hold that truths like this are _not_ mutable, he never tries to tell us to what kinds of truths he would limit mutability, nor how they differ from such as this.