=Relation of the True and the Good.=--There is a necessary and indissoluble connection between truth and usefulness. We all at once admit this connection in one direction. We all admit that a truth must eventually have its useful application. It may not be _now_, nor in ten years, nor in a century, nor even in a millennium, but some time in the future it will vindicate its usefulness. No truth is trivial or useless in its relation to human life, for man is a part of Nature, and his life must be in accordance with the laws of Nature. Every one admits this, but not every one admits the converse proposition, viz., that whatever doctrine or belief, in the long run and throughout the history of human advancement, has tended to the betterment of our race, must have in it an element of truth by virtue of which it has been useful; for man’s good can not be in conflict with the laws of Nature. Also, whatever in the long run and in the final outcome tends to the bad in human conduct, ought to be received, even by the honest truth-seeker, with distrust as containing essential error. The reason of this will now be further explained. =Relation of Philosophy to Life.=--There are three primary divisions of our psychical nature, viz., sensuous, intellectual, and volitional or moral. There are three corresponding primary processes necessary to make a complete rational and satisfactory philosophy: (1) There is first the _instreaming_ of the external world through the senses, as impressions. These we call facts or phenomena. (2) The elaboration of these facts within, by the _intellect_, into a compact, consistent structure. This we call knowledge. (3) The outgoing of this knowledge by the _will_ into the world as right or wise conduct. Now these three are all equally necessary. All these three portions of our complex nature are equally urgent to be satisfied.[39] But, unfortunately, scientific workers are too apt to think only 1 and 2 necessary--that true facts elaborated into consistent theory are all we need care for. Theologians and metaphysicians, on the other hand, seem to think only 2 and 3 necessary. They elaborate a theory consistent in all its parts, exquisitely woven in beautiful and delicate pattern, and apparently satisfactory in its application to the right conduct of life, but are less careful to inquire whether it is in harmony with facts derived from the senses. But, we repeat, all three are equally necessary. The first gathers the materials, the second constructs the edifice, the third, by _use_, by practical application, _tests_ whether it be a fit building to live in, whether it is constructed on sound architectural principles. The tendency of the olden time was to neglect the first, the tendency of the present time is to neglect the third. But we repeat with stronger emphasis that this third element is equally necessary. All admit that successful application in art is the surest test of the truth of science.