[178] As to the term "Chance" which he frequently used, Mr. Darwin wrote in one place (_Origin of Species_, Opening passage of c. v.): "I have hitherto sometimes spoken as if the variations--so common and multiform with organic beings under domestication, and in a lesser degree with those in a state of nature--had been due to chance. This, of course, is a wholly incorrect expression, but it serves to acknowledge plainly our ignorance of the cause of each particular variation." It is obvious, however, that this explanation only serves to show that, as we have heard him confess, Mr. Darwin was anything but a clear thinker, for it is absolutely meaningless if applied to his mention of "Chance" quoted in the text above. He could not possibly mean that the mind refuses to regard the world as the outcome of a cause whereof we know nothing, for that is just what he thinks it is. Mr. Darwin, in fact, instinctively recognized, as every man of common-sense must do, that if not due to purpose, the order of Nature is due to chance, according to the true and legitimate use of the word, and thus he commonly employed it. Occasionally however he endeavoured, following Huxley and others, to defend himself against the reproach of relying upon such a factor.--_Vid. sup._, c. xii. [179] Although at first Mr. Darwin appeared to restrict his system to _species_, very soon, as was but natural, it was extended to the production of new _genera_, and even of divisions of the organic kingdoms yet wider asunder. Thus--apart from the most famous instance of all, treated by Darwin himself in his _Descent of Man_--it is now a cardinal point with Evolutionists generally that all the higher forms of life are descended from the lowest, and that even far up the line of development, creatures apparently the most diverse have sprung from one identical ancestor. Thus amongst vertebrates it is considered certain that Birds and Reptiles are branches of the same stock,--and, still farther on, that at least all placental mammals--bats and whales, elephants and mice--trace their pedigree to some common progenitor. [180] _Origin of Species_, v. [181] _Ibid._, c. vii. [182] _Ibid._, c. vi. [183] "I remember well the time when the thought of the eye made me cold all over, but I have got over this stage of the complaint, and now some small trifling particulars of structure often make me feel very uncomfortable. The sight of a feather in a peacock's tail, whenever I gaze at it, makes me sick." (_C. Darwin to Asa Gray, April 3, 1860._) [184] It will help to understand the nature of the task thus imposed upon Natural Selection, to consider what Lord Grimthorpe writes on this subject (_Origin of the Laws of Nature_, p. 103):