Look upon the earth then as being once in this hot fluid condition. It turns slowly round upon its axis and cools. I cannot trace the whole of the process, but before it arrived at its present condition there must have been crackings and burstings and eruptions; and so continents and islands and mountains would be formed; but upon the whole, even in the wildest times, the process would be very gentle, for the highest mountains on the earth's surface are but as the down upon the surface of a peach. Then upon this globe appear creatures suited to its condition; and the eye which could have watched the world in its progress would have seen animals of successively higher types occupying the earth's surface, till at length that surface was spotted with cities built by the hand of man, and the ocean studded with his ships. It is impossible to guess the time which must have elapsed between the epoch when the earth was a hot revolving mass of fluid, and the epoch in which we live; neither is it very possible to say, though it is possible to guess, what would have been the successive scenes presented by the earth to the eye which should have witnessed the whole of the changes; but whatever may have been the nature of the changes, this conclusion is inevitable, namely, that there has been a progression of some kind from the fluidity of the primæval dead revolving mass to the inhabited world of this nineteenth century; it matters not for my argument whether the progression, so far as animal life is concerned, has been due to natural selection, or to such a process as that advocated by the author of "Vestiges of Creation," or to successive and distinct creative acts; the fact holds good, upon any hypothesis, that the Almighty Creator has produced that universe which we see, not by one act, but by a gradual and apparently very slow creative process, whether continuous or discontinuous it matters not for my purpose to inquire. Now this course of nature is strikingly analogous to that gradual mode of proceeding which is alleged to belong to revelation; and any difficulty which belongs to one appears to attach equally to the other. Nay, if we are to give any weight to the most recent physical speculations, it may be fairly argued that the difficulties connected with revelation are but as trifles compared with those which nature presents. I refer to those views of which the latest exposition is to be found in Mr. Darwin's "Descent of Man." Let me touch upon those views for a moment.