On the side of things, _reality_ is identified with truth; then on the principle that two things that are equal to the same thing are equal to each other, truth as idea and truth as reality are taken to be one and the same thing. Wherever there is an improved or tested idea, an idea which has made good, there is a concrete existence in the way of a completed or harmonized situation. The same activity which proves the idea constructs an inherently satisfied situation out of an inherently dissentient one,--for it is precisely the capacity of the idea as an aim and method of action to determine such transformation that is the criterion of its truth. Now unless all the elements in the situation are held steadily in view, the specific way in which the harmonized reality affords the criterion of truth (namely, through its function of being the last term of a process of active determination) is lost from sight; and the achieved existence in its merely existent character, apart from its practical or fulfilment character, is treated as The Truth. But when the reality is thus separated from the process by which it is achieved, when it is taken just as given, it is neither truth nor a criterion of truth. It is a state of facts like any other. The achieved telephone is a criterion of the validity of a certain prior idea in so far as it is the fulfilment of activities that embody the nature of that idea, but just as telephone, as a machine actually in existence, it is no more truth nor criterion of truth than is a crack in the wall or a cobble-stone on the street.
The intervening term that mediates and completes the confusion of truth with ideas on one hand and “reality” on the other, is, I think, the fact that ideas after they have been tested in action are employed in the development and grounding of further beliefs. There are cases in which an idea ceases to exist as idea as soon as it is made true; this is so as matter of fact and it is impossible to conceive any reason why it should not be so in point of theory. Such is the case, I take it, with a large part--possibly the major portion--of the ideas that mediate the smaller and transient crises of daily practice. I cannot imagine the situation in which the truth to which I have referred above--the verification of a certain idea about a certain noise--would ever function again as truth--save as I have given it a function in this paper by using it as a corroboration of a certain theory. Such ideas mostly cease, giving way to a matter-of-fact status: say, the perception of the noisy street-car. One at the time may say “My idea regarding that noise was a true idea”; or one may not even go so far as that, he may just stop with the eventual perception. But the tested idea need not ever recur as a factor of proof in any other problem. Such, however, is conspicuously not the case with our scientific ideas. In its first value, the idea or hypothesis of gravitation entertained by Newton, stood, when verified, on exactly the same level as the hypothesis regarding the noise in the street. Theoretically, that truth might have been so isolated that its truth character would disappear from thought as soon as a certain factual condition was ascertained. But practically quite the opposite has happened. The idea operates in many other inquiries, and operates no longer as mere idea, but as _proved_ idea. Such truths get an “eternal” status;--one irrespective of application just now and here, because there are so many nows and heres in which they are useful. Just as to say an idea was true all the time is a way of saying _in retrospect_ that it has come out in a certain fashion, so to say that an idea is “eternally true” is to indicate _prospective_ modes of application which are indefinitely anticipated. Its meaning, therefore, is strictly pragmatic. It does not indicate a property inherent in the idea as intellectualized existence, but denotes a property of use and employment. Always at hand when needed is a good enough eternal for reasonably minded persons.
