utility is a property which comes and goes--which belongs to a given idea at one time, and does not belong to it at another, that anyone who says that the true is the useful naturally seems not to be overlooking this obvious fact, but to be suggesting that truth is a property which comes and goes in the same way. It is, in this way I think, that the "instrumental" view of truth is connected with the view that truth is "mutable." Professor James does, I think, imply that truth is mutable in just this sense--namely, that one and the same idea may be true at some of the times at which it occurs, and not true at others, and this is the view which I have next to consider. (II) Professor James seems to hold, generally, that "truth" is mutable. And by this he seems sometimes to mean that an idea which, when it occurs at one time, is true, _may,_ when it occurs at another time, not be true. He seems to hold that one and the same idea _may_ be true at one time and false at another. That it _may_ be, for I do not suppose he means that all ideas do actually undergo this change from true to false. Many true ideas seem to occur but once, and, if so, they, at least, will not actually be true at one time and false at another, though, even with regard to these, perhaps Professor James means to maintain that they _might_ be false at another time, if they were to occur at it. But I am not sure that he even means to maintain this with regard to _all_ our true ideas. Perhaps he does not mean to say, with regard to _all_ of them, even that they _can_ change from true to false. He speaks, generally, indeed, as if truth were mutable; but, in one passage, he seems to insist that there is a certain class of true ideas, none of which are mutable in this respect. "_Relations among purely mental ideas,"_ he says (p. 209), "form another sphere where true and false beliefs obtain, and here the beliefs are absolute or unconditional. When they are true they bear the name either of definitions or of principles. It is either a principle or a definition that 1 and 1 make 2, that 2 and 1 make 3, and so on; that white differs less from grey than it does from black; that when the cause begins to act the effect also commences. Such propositions hold of all possible 'ones,' of all conceivable 'whites,' 'greys,' and 'causes.' The objects here are mental objects. Their relations are perceptually obvious at a glance, and no sense-verification is necessary. Moreover, once true, always true, of those same mental objects. Truth here has an 'eternal' character. If you can find a concrete thing anywhere that is 'one' or 'white' or 'grey' or an 'effect,' then your principles will everlastingly apply to it." Professor James does seem here to hold that there are true ideas, which once true, are always true. Perhaps, then, he does not hold that _all_ true ideas are mutable. Perhaps he does not even hold that all true ideas, _except_ ideas of this kind, are so.