with a spirit of scientific research could be counted on one's fingers. It is a striking fact in the history of man that, out of the many centuries he has inhabited the earth, so few have been productive of any useful knowledge. Throw away everything that had been done previous to the fifteenth century, and the loss would have been by no means irreparable. Add to the productive period twenty centuries, and we embrace the whole. Think of the average life of fourscore men spanning the totality of human knowledge! Truly, science is in its infancy. What were the speculations of the men who existed a few centuries prior to our era, we have no record. After the dim poetical aspirations which compose the earliest known philosophy, there emerges a pseudo-scientific natural philosophy, which, disdaining the shackles that a constant reference to the phenomena of nature would impose upon its flights, attempts at once to solve the problem of the universe. Like the famous German, who, instead of going to see the camel he was to describe, pursued the easier and more fascinating method of evolving him from his own inner consciousness, the Greek philosopher evolved the universe from his.
A modern writer, who certainly can not be accused of want of sympathy with a deductive philosophy, in comparing the relative merits of the a priori and a posteriori methods, observes that, although the latter may in general come somewhat nearer the facts of nature, yet, as it can never embrace all the phenomena in its inductions, it can never arrive at the whole truth; while the a priori method, if it chance to hit upon the right formula, has the whole universe, so to speak, at its fingers' ends. While we may readily admit the sublimity of the attempt to reach out and grasp the hidden springs of nature, stubborn facts constrain us to assert its impracticability. The diffuse light of mental theory must be concentrated to a small focus in order to produce any visible effect.
Knowledge is the concomitant of the progressive limitation of our powers. As long as man assumes that he contains within himself the premises of knowledge, so long will it elude his grasp. Not until experience has compelled him to doubt the validity of his mental concepts when applied to nature, and has forced him to have recourse to facts only, has man taken the first steps in the paths of science.
That one learns the boundlessness of knowledge only in proportion to his own acquirements is a saying famous only for its triteness. What are certainties to the ignorant are uncertainties to the intelligent. What are dogmas to the blind followers of a fanatical priesthood are for ever insoluble problems to the man of science. The ignorant savage—who can not count beyond five; who has no abstract names in his vocabulary; who knows nothing of the use of pronouns; who uses words denoting the commonest things and most usual actions only—possesses knowledge differing so widely in degree from ours as almost to constitute a difference of kind. For him nature has no problems.