How completely all difficulty vanishes from the facts so pleasantly told in this passage when we bear in mind the true nature of personal identity, the ordinary working of memory, and the vanishing tendency of consciousness concerning what we know exceedingly well. My last instance I take from M. Ribot, who writes:--"Gratiolet, in his _Anatomie Comparee du Systems Nerveux_, states that an old piece of wolf's skin, with the hair all worn away, when set before a little dog, threw the animal into convulsions of fear by the slight scent attaching to it. The dog had never seen a wolf, and we can only explain this alarm by the hereditary transmission of certain sentiments, coupled with a certain perception of the sense of smell." ("Heredity," p. 43.) I should prefer to say "we can only explain the alarm by supposing that the smell of the wolf's skin"--the sense of smell being, as we all know, more powerful to recall the ideas that have been associated with it than any other sense--"brought up the ideas with which it had been associated in the dog's mind during many previous existences"--he on smelling the wolf's skin remembering all about wolves perfectly well. CONCLUDING REMARKS. (FROM CHAPTER XV. OF LIFE AND HABIT.) Here, then, I leave my case, though well aware that I have crossed the threshold only of my subject. My work is of a tentative character, put before the public as a sketch or design for a, possibly, further endeavour, in which I hope to derive assistance from the criticisms which this present volume may elicit. {125} Such as it is, however, for the present I must leave it. We have seen that we cannot do anything thoroughly till we can do it unconsciously, and that we cannot do anything unconsciously till we can do it thoroughly; this at first seems illogical; but logic and consistency are luxuries for the gods, and the lower animals, only. Thus a boy cannot really know how to swim till he can swim, but he cannot swim till he knows how to swim. Conscious effort is but the process of rubbing off the rough corners from these two contradictory statements, till they eventually fit into one another so closely that it is impossible to disjoin them. Whenever we see any creature able to go through any complicated and difficult process with little or no effort--whether it be a bird building her nest, or a hen's egg making itself into a chicken, or an ovum turning itself into a baby--we may conclude that the creature has done the same thing on a very great number of past occasions. We found the phenomena exhibited by heredity to be so like those of memory, and to be so inexplicable on any other supposition than that they were modes of memory, that it was easier to suppose them due to memory in spite of the fact that we cannot remember having recollected, than to believe that because we cannot so remember, therefore the phenomena cannot be due to memory.