It should be observed also that the distinction between the organism and its surroundings—on which both systems are founded—is one that cannot be so universally drawn as we find it convenient to allege. There is a debatable ground of considerable extent on which _res_ and _me_, ego and non ego, luck and cunning, necessity and freewill, meet and pass into one another as night and day, or life and death. No one can draw a sharp line between ego and non ego, nor indeed any sharp line between any classes of phenomena. Every part of the ego is non ego _quâ_ organ or tool in use, and much of the non ego runs up into the ego and is inseparably united with it; still there is enough that it is obviously most convenient to call ego, and enough that it is no less obviously most convenient to call non ego, as there is enough obvious day and obvious night, or obvious luck and obvious cunning, to make us think it advisable to keep separate accounts for each. I will say more on this head in a following chapter; in this present one my business should be confined to pointing out as clearly and succinctly as I can the issue between the two great main contending opinions concerning organic development that obtain among those who accept the theory of descent at all; nor do I believe that this can be done more effectually and accurately than by saying, as above, that Mr. Charles Darwin (whose name, by the way, was “Charles Robert,” and not, as would appear from the title-pages of his books, “Charles” only), Mr. A. R. Wallace, and their supporters are the apostles of luck, while Erasmus Darwin and Lamarck, followed, more or less timidly, by the Geoffroys and by Mr. Herbert Spencer, and very timidly indeed by the Duke of Argyll, preach cunning as the most important means of organic modification. * * * * * NOTE.—It appears from “Samuel Butler: A Memoir” (II, 29) that Butler wrote to his father (Dec. 1885) about a passage in Horace (near the beginning of the First Epistle of the First Book)— Nunc in Aristippi furtim praecepta relabor, Et mihi res, non me rebus subjungere conor. On the preceding page he is adapting the second of these two verses to his own purposes.—H. F. J. Chapter VII (_Intercalated_) Mr. Spencer’s “The Factors of Organic Evolution” SINCE the foregoing and several of the succeeding chapters were written, Mr. Herbert Spencer has made his position at once more clear and more widely understood by his articles “The Factors of Organic Evolution” which appeared in the _Nineteenth Century_ for April and May, 1886. The present appears the fittest place in which to intercalate remarks concerning them. Mr. Spencer asks whether those are right who regard Mr. Charles Darwin’s theory of natural selection as by itself sufficient to account for organic evolution.