Embryos think with each stage of their development that they have now reached the only condition that really suits them. This, they say, must certainly be their last, inasmuch as its close will be so great a shock that nothing can survive it. Every change is a shock; every shock is a pro tanto death. What we call death is only a shock great enough to destroy our power to recognize a past and a present as resembling one another.
I remember one incident which bears upon this part of the treatise. The gentleman who gave it to me had asked to see my tobacco-pipe; he examined it carefully, and when he came to the little protuberance at the bottom of the bowl he seemed much delighted, and exclaimed that it must be rudimentary. I asked him what he meant."Sir," he answered, "this organ is identical with the rim at the bottom of a cup; it is but another form of the same function. Its purposes must have been to keep the heat of the pipe from marking the table upon which it rested. You would find, if you were to look up the history of tobacco-pipes, that in early specimens this protuberance was of a different shape to what it is now. It will have been broad at the bottom, and flat, so that while the pipe was being smoked the bowl might rest upon the table without marking it. Use and disuse must have come into play and reduced the function its present rudimentary condition. I should not be surprised, sir," he continued, "if, in the course of time, it were to become modified still farther, and to assume the form of an ornamental leaf or scroll, or even a butterfly, while in some cases, it will become extinct.
If, again, the most superficial introspection teaches the physiologist that his conscious life is dependent upon the mechanical adjustments of his body, and that inversely his body is subjected with certain limitations to his will, then it only remains for him to make one assumption more, namely, that this mutual interdependence between the spiritual and the material is itself also dependent on law, and he has discovered the bond by which the science of the matter and the science of consciousness are united into a single whole.
We want words to do more than they can. We try to do with them what comes to very much like trying to mend a watch with a pickaxe or to paint a miniature with a mop; we expect them to help us to grip and dissect that which in ultimate essence is as ungrippable as shadow. Nevertheless there they are; we have got to live with them, and the wise course is to treat them as we do our neighbours, and make the best and not the worst of them.