Page:American Journal of Sociology Volume 1.djvu/151

 Rh are doubtless as dead as our moon which has neither water nor air. The sun is an enormous mass of matter 1,400,000 times as large as the earth and containing 99.866 per cent, of the matter of the whole solar system. Yet it is known to be in a state of such intense heat that some of the metals which it requires great heat even to melt are not only melted but volatilized. No one therefore conceives that there can be any life or intelligence on the sun. Think of the optimism that is required to make out a favorable case from such facts! Even if all parts of all the planets were inhabited they would together make only $$\tfrac{1}{47}$$ part of the area of the sun's surface, while that of the earth alone is only $$\tfrac{1}{12552}$$. But our sun is only one of the lesser fixed stars, and it may be assumed that similar conditions prevail throughout the universe.

If we contemplate the earth itself we find an analogous state of things. The period that man has inhabited the earth is very small compared with what we know its age to be. We can scarcely speak more than relatively, but the certainty is as great as if we could fix dates for geologic events. Of the enormous thickness, (150,000 feet) of sedimentary rocks that can be measured from the earliest to the latest  those that have been deposited since man made his appearance form only a minute fraction. In quite recent times some attempts have been made to determine approximately in years the age of the earth. The results vary greatly but are constantly growing more uniform. The physicists, astronomers, and geologists, who all use widely different data and methods, and who formerly differed greatly, have latterly come to a much closer agreement, which argues some approach to the truth. Using the most moderate ones, the crust of the earth seems to have been fully formed not less than 100,000,000 years ago. Some form of life has probably existed on it during nearly all that period. But paleontology teaches that life, though slowly increasing in development, was of too low an order to be capable of intelligence until man appeared. Yet what are the estimates of man's entire historic and prehistoric existence? The most extravagant of them do