Page:Popular Science Monthly Volume 18.djvu/708

690 it under a microscope of high power, and the corpuscles are seen hurrying hither and thither as if (to use a quite appropriate simile) their life depended upon it. Repeat the process, and new complexities are seen. Increasing the power of our senses artificially by the use of instruments has given us a vastly enlarged conception of nature; but every increase in knowledge shows us more clearly the limitation of the knowledge we possess. Truly, there are more things in heaven and earth than are dreamed of in our philosophy.

Science is continually teaching us the lesson that the universe is larger and more complex than formerly supposed. Old geographers, guided by an egoistic impulse, placed their own country in the center of the known earth; early astronomers placed the earth in the center of the universe. Later, that position of honor was given to the sun. The influence of mental concepts and the desire for system, even where none is discernible, induce some astronomers to locate the center of the sidereal system somewhere in the region of the Pleiades; but, even should this attempt prove successful, we should be no nearer the discovery of the center of the universe. Place a grain of sand thirty feet from an orange, and you have, approximately, the relative distances and dimensions of the earth and sun. Nearly one thousand feet beyond would be the planet Neptune—the outermost planet of our system—while more than twelve hundred miles would have to be traversed before arriving at the nearest fixed star. Even on this miniature scale, our fractions of inches grow to miles, and man finds himself immeasurably dwarfed, even in the presence of the known. He sees whole systems drifting through space. In a much broader sense than Emerson meant, we are like ships upon an unknown ocean, knowing neither whence we came nor whither we are bound.

It is fascinating, no doubt, to construct theories of universe-reaching proportions. It has been truly said that—

Perhaps such employments are elevating. Such, at least, is the claim of those who affect to despise what they superciliously term the bread-and-butter sciences. Admit all they claim; still, their conceptions of nature are worthless until verified.

In this brief sketch of past thought, we have seen that it was only as man has been content to acquire knowledge patiently, slowly, and arduously, by what are now known as scientific methods, that his knowledge has been of any practical value. Theorize as widely as he may, constant verification is the only criterion of a theory's validity. Fact must be the point of departure and the point of return of all