As soon as I had finished this, I returned to the old subject, on which I had already been engaged for nearly a dozen years as continuously as other business would allow, and proposed to myself to see not only machines as limbs, but also limbs as machines. I felt immediately that I was upon firmer ground. The use of the word “organ” for a limb told its own story; the word could not have become so current under this meaning unless the idea of a limb as a tool or machine had been agreeable to common sense. What would follow, then, if we regarded our limbs and organs as things that we had ourselves manufactured for our convenience? The first question that suggested itself was, how did we come to make them without knowing anything about it? And this raised another, namely, how comes anybody to do anything unconsciously? The answer “habit” was not far to seek. But can a person be said to do a thing by force of habit or routine when it is his ancestors, and not he, that has done it hitherto? Not unless he and his ancestors are one and the same person. Perhaps, then, they _are_ the same person after all. What is sameness? I remembered Bishop Butler’s sermon on “Personal Identity,” read it again, and saw very plainly that if a man of eighty may consider himself identical with the baby from whom he has developed, so that he may say, “I am the person who at six months old did this or that,” then the baby may just as fairly claim identity with its father and mother, and say to its parents on being born, “I was you only a few months ago.” By parity of reasoning each living form now on the earth must be able to claim identity with each generation of its ancestors up to the primordial cell inclusive. Again, if the octogenarian may claim personal identity with the infant, the infant may certainly do so with the impregnate ovum from which it has developed. If so, the octogenarian will prove to have been a fish once in this his present life. This is as certain as that he was living yesterday, and stands on exactly the same foundation. I am aware that Professor Huxley maintains otherwise. He writes: “It is not true, for example, . . . that a reptile was ever a fish, but it is true that the reptile embryo” (and what is said here of the reptile holds good also for the human embryo), “at one stage of its development, is an organism, which, if it had an independent existence, must be classified among fishes.” {17}