"It is often asserted, in order to unsettle confidence in these particular teachings of geology, that geology is a changing science. In this connection the remark conveys an erroneous impression. Geology is a progressive science; and all its progress tends to establish more firmly these two principles: (1) The slow progress of creation through secondary causes, as explained; and (2) the progress by periods analogous to the days of Genesis." I have, I trust, shown that the principal objections to the lengthening of the Mosaic days into great cosmical periods are of a character too light and superficial to deserve any regard. I shall now endeavor to add to the internal evidence previously given some considerations of an external character which support this view. 1. The fact that the creation was progressive, that it proceeded from the formation of the raw material of the universe, through successive stages, to the perfection of living organisms, if we regard the analogy of God's operations as disclosed in the geological history of the earth and in the present course of nature, must impress us with a suspicion that long periods were employed in the work. God might have prepared the earth for man in an instant. He did not choose to do so, but on the contrary proceeded step by step; and the record he has given us does not receive its full significance nor attain its full harmony with the course of geological history, unless we can understand each day of the creative week as including a long succession of ages. 2. We have, as already explained, reason to believe that the seventh day at least has been of long duration. At the close of the sixth, God rested from all his work of material creation, and we have as yet no evidence that he has resumed it. Neither theologians nor evolutionists will, I presume, desire to maintain that any strictly creative acts have occurred in the modern period of geology. We know that the present day, if it is the seventh, has lasted already for at least six thousand years, and, if we may judge from the testimony of prophecy, has yet a long space to run, before it merges in that "new heaven and new earth" for which all believers look, and which will constitute the first day of an endless sabbatism. 3. The philosophical and religious systems of many ancient nations afford intimations of the somewhat extensive prevalence in ancient times of the notion of long creative periods, corresponding to the Mosaic days. These notions, in so far as they are based on truth, are probably derived from the Mosaic narrative itself, or from the primitive patriarchal documents which may have formed the basis of that narrative. They are, no doubt, all more or less garbled versions, and can not be regarded as of any authority, but they serve to show what was the interpretation of the document in a very remote antiquity. I have collected from a variety of sources the following examples: