But lest the man of science, the man of dominantly reflective habits, be puffed up with his own conceits, he must bear in mind that practical application--that is, experiment--is a condition of his own calling, that it is indispensable to the institution of knowledge or truth. Consequently, in order that he keep his own balance, it is needed that his findings be everywhere applied. The more their application is confined within his own special calling, the less meaning do the conceptions possess, and the more exposed they are to error. The widest possible range of application is the means of the deepest verification. As long as the specialist hugs his own results they are vague in meaning and unsafe in content. That individuals in every branch of human endeavor should be experimentalists engaged in testing the findings of the theorist is the sole final guaranty for the sanity of the theorist. FOOTNOTES: [78] _Scientific Method in Philosophy_, p. 57. [79] The analytic realists have shown a peculiar disinclination to discuss the nature of future consequences as terms of propositions. They certainly are not identical with the mental act of referring to them; they are "objective" to it. Do they, therefore, already subsist in some realm of subsistence? Or is subsistence but a name for the fact of logical reference, leaving the determination of the meaning of "subsistence" dependent upon a determination of the meaning of "logical"? More generally, what is the position of analytic realism about the future? [80] Supposing the question to be that of some molten state of the earth in past geologic ages. Taken as the complete subject-matter of a proposition--or science--the facts discovered cannot be regarded as causative of, or a mechanism of, the appearance of life. For by definition they form a closed system; to introduce reference to a future event is to deny the definition. Contrariwise, a statement of that past condition of the earth as a mechanical condition of the later emergence of life means that that past stage is taken not merely as past, but as in process of transition to its future, as in process of alteration in the direction of life. Change in this direction is an integral part of a statement of the early stage of the earth's history. A purely geologic statement may be quite accurate in its own universe of discourse and yet quite incomplete and hence inaccurate in another universe of discourse. That is to say, a geologist's propositions may accurately set forth a prior state of things, while ignoring any reference to a later state entailed by them. But a would-be philosophy may not ignore the implied future. [81] _Philosophical Essays_, pp. 104, 105. [82] _Sixth Meditation._ [83] _Principles of Philosophy_, p. 90. [84] _Treatise of Human Nature_, Part III, sec. iii.