He expressed the wish to induce men who had sufficient knowledge of the particular branches of science, to employ their acquired talents in promoting general science, or knowledge of the great system, where ends and means are wisely adjusted in the constitution of the material universe. Philosophy, he says, is surely the ultimate end of human knowledge, or the object at which all sciences properly must aim. Sciences no doubt should promote the arts of life; but, he proceeds, what are all the arts of life, or all the enjoyments of mere animal nature, compared with the art of human happiness, gained by education and brought to perfection by philosophy? Man must learn to know himself; he must see his station among created things; he must become a moral agent. But it is only by studying things in general that he may arrive at this perfection of his nature. "To philosophize, therefore, without proper science, is in vain; although it is not vain to pursue science, without proceeding to philosophy." In the early part of 1785 Dr. Hutton presented his _Theory of the Earth_ in ninety-six pages of perfectly lucid English. The globe is studied as a machine adapted to a certain end, namely, to provide a habitable world for plants, for animals, and, above all, for intellectual beings capable of the contemplation and the appreciation of order and harmony. Hutton's theory might be made plain by drawing an analogy between geological and meteorological activities. The rain descends on the earth; streams and rivers bear it to the sea; the aqueous vapors, drawn from the sea, supply the clouds, and the circuit is complete. Similarly, the soil is formed from the overhanging mountains; it is washed as sediment into the sea; it is elevated, after consolidation, into the overhanging mountains. The earth is more than a mechanism, it is an organism that repairs and restores itself in perpetuity. Thus Hutton explained the composition, dissolution, and restoration of land upon the globe on a general principle, even as Newton had brought a mass of details under the single law of gravitation. Again, as Newton had widened man's conception of space, so Hutton (and Buffon) enlarged his conception of time. For the geologist did not undertake to explain the _origin_ of things; he found no vestige of a beginning,--no prospect of an end; and at the same time he conjured up no hypothetical causes, no catastrophes, or sudden convulsions of nature; neither did he (like Werner) believe that phenomena now present, were once absent; but he undertook to explain all geological change by processes in action now as heretofore. Countless ages were requisite to form the soil of our smiling valleys, but "Time, which measures everything in our _idea_, and is often deficient to our schemes, is to nature endless and as nothing." The calcareous remains of marine animals in the solid body of the earth bear witness of a period to which no other species of chronology is able to remount.