THE doctrine of Evolution has been applied not only to the formation of all created things, but to the development of human knowledge; and this with perfect justice, though with some risk of misunderstanding. It is certain, and, indeed, it is obvious, that knowledge grows. The ordinary experience of mankind becomes larger and clearer in the course of time, and the systematised experience which we call Science makes the same progress in still greater measure and with more assurance.

Our Science has been built on the labours of scientific men in past ages. New generalisations imagined by one thinker, new crucial experiments devised by another, new instruments of observation invented by another,—these have been the steps by which Science lias grown and established its authority and enlarged its dominion. When or by whom the first steps were made we have no record. No mathematician that ever lived showed greater natural power of intellect than he, whoever he was, who first saw that the singular contained the universal; but we know neither his name nor his age, nor his birthplace nor his race. But after those first steps had been taken, we know who have been the leaders in scientific advance.