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Show 154 MR. DARWIN'S WORK AND cerned, man differs to no greater extent from the animals which are immediately below him than these do from other members of the same order. Upon the other hand, there is no one who estimates more highly than I do the dignity of human nature, and the width of the gulf in intellectual and 1noral matters, which lies between man and the whole of the lower creation. But I find this very argument brought forward vehemently by some. " You say that man has proceeded fr~m a modification of some lower animal, and you take pa1ns to prove that the structural differences which are said to exist in nis brain do not exist at all, and you teach that all functions, intellectual, moral, and others are the expression or the result, in the long run, o'f Rtructures, aud of the molecular forces which the exer t." I t 1. s qu1. te true that I do so. y "Well, but," I am told at once, somewhat triumphantly, "you say in the same breath that there is a <rreat moral and intellectual chasm between man and 0 the lower animals. I-Iow is this possible when you declare that moral and intellectual characteristics depend on structure, and yet tell us that there is no such o·ulf between the structure of man and that of the lo~er animals?" I think that objection is based upon a misconception of the real relations w hieh exist between structure and function, bet,veen mechanism and work. Function is the expression of molecular forces and arrangements no doubt; but, does it follow from this, that variation in function so depends upon variation in ~lructure that the former is always exactly proportioned to the latter? If there is .no such relation, if the variation in function THE PHENOMENA OF ORGANIC NATURE. 155 which follows on a variation in structure, may be enormously greater than the variation of the structure, then, you see, the objection falls to the ground. Take a couple ofwatches-made by the same maker, and as completely alike as possible; set them upon the table, and the function of each-which is its rate of going -will be performed in the same manner, and you shall be able to distinguish no difference between them; but let me take a pair of pincers, and if my hand is steady enough to do it, let me just lightly crush together the bearings of the balance-wheel, or force. to a slightly different angle the teeth of the escapement of one of them, and of course you know the immediate result will be that the watch, so treated, from that moment will cease to go. But what proportion is there between the structural alteration and the functional result ? Is it not perfectly obvious that the alteration is of the minutest kind, yet that slight as it is, it has produced an infinite difference in the performance of the functions of these two instruments·? Well, now, apply that to the present question. What is it that constitutes and makes man what he is? What is it but his power of language-that language giving him the means of recording his experiencemaking every genm·ation somewhat wiser than its predecessor,-more in accordance with the established order of the universe? What is it but this power of speech, of recording experience, which enables men to be men-looking before and after and, in some dim sense, understanding the working of this wondrous universe-and which distinguishes 1nan from the whole of the brute world? |