August 9, 1894] 



NA TURE 



343 



capable of explaining the adaptation of organisms without as- 

 suming the help of a principle of design." 



There is the difficulty. We cannot demonstrate the process 

 of natural selection in detail ; we cannot even, with more or 

 less ease, imagine it. It is purely hypothetical. No man, so far 

 as we know, has ever seen it at work. An accidental variation 

 may have been perpetuated by inheritance, and in the struggle 

 for existence the bearer of it may have replaced, by virtue of 

 the survival of the fittest, his less improved competitors ; but as 

 far as we know no man or succession of men have ever ob- 

 served the whole process in any single case, and certainly no 

 man has recorded the observation. Variation by artificial %eXtQ.- 

 tion, of course, we know very well ; but the intervention of the 

 cattle breeder and the pigeon fancier is the essence of artificial 

 selection. It is effected by their action in crossing, by their skill 

 in bringing the right mates together to produce the progeni- 

 ture they want. But in natural selection who is to supply the 

 breeder's place ? Unless the crossing is properly arranged, the 

 new breed will never come into being. What is to secure 

 that the two individuals of opposite sexes in the primeval 

 forest, who have been both accidentally blessed with the same 

 advantageous variation, shall meet, and transmit by inheritance 

 that variation to their successors ? Unless this step is made 

 good, the modification will never get a start ; and yet there is 

 nothing to insure that step, except pure chance. Vhe law of 

 chances takes the place of the cattle breeder and the pigeon 

 fancier. The biologists do well to ask for an immeasurable ex- 

 panse of time, if the occasional meetings of advantageously 

 varied couples from age to age are to provide the pedigree of 

 modifications which unite us to our ancestor the jelly-fish. Of 

 course the straggle for existence, and the survival of the fittest, 

 would in the long run secure the predominance of the stronger 

 breed over the weaker. But it would be of no use in setting the 

 improved breed going. There would not be time. No possible 

 variation which is known to our experience, in the short time 

 that elapses in a single life between the moment of maturity and 

 the age of reproduction, could enable the varied individual to 

 clear the field of all competitors, either by slaughtering or 

 starving them out. But unless the struggle for existence took 

 this summary and internecine character, there would 

 be nothing but mere chance to secure that the 

 advantageously varied bridegroom at one end of the 

 wood should meet the bride, who by a happy con- 

 tingency had been advantageously varied in the same 

 direction at the same time at the other end of the wood. 

 It would be a mere chance if they ever knew of each other's 

 existence- — a still more unlikely chance that they should resist 

 on both sides all temptations to a less advantageous alliance. 

 But unless they did so, the new breed would never even begin, 

 let alone the question of its perpetuation after it had begun. 

 I think Prof. Weismann is justified in saying that we cannot, 

 either with more or less ease, imagine the process of natural 

 selection. 



It seems strange that a philosopher of Prof. Weismann's 

 penetration should accept as established a hypothetical process 

 the truth of which he admits that he cannot demonstrate in 

 detail, and the operation of which he cannot even imagine. 

 The reason that he gives seems to me instructive of the great 

 danger scientific research is running at the present time — the 

 acceptance of mere conjecture in the name and place of know- 

 ledge, in preference to making frankly the admission that no 

 certain knowledge can be attained. "We accept natur.il 

 selection," he says, " because we must — because it is the only 

 possible explanation that we can conceive." As a politician, I 

 know that argument very well. In political controversy it is 

 sometimes said of a disputed proposal that it " holds the field," 

 that it must be accepted because no possible alternative has been 

 suggested. In politics there is occasionally a certain validity in 

 the argument, for it sometimes happens that some definite course 

 must be taken, even though no course is free from objection. But 

 such a line of reasoning is utterly out of place in science. 

 We are under no obligation to find a theory, if the facts will 

 not provide a sound one. To the riddles which nature pro- 

 pounds to us the profession of ignorance must constantly be 

 our only reasonable answer. The cloud of impenetrable 

 mystery hangs over the development and still more over the 

 origin of life. If we strain our eyes to pierce it, with the 

 foregone conclusion that some solution is and must be attain- 

 able, we shall only mistake for discoveries the figments of our 

 own imagination. Prof. Weismann adds another reason for 



NO. 1293, VOL. 50] 



his belief in natural selection, which is certainly characteristic 

 of the time in which we live. " It is inconceivable," he says, 

 "that there should be another principle capable of explaining 

 the adaptation of organisms without assuming the help of a 

 principle of design." The whirligig of time assuredly brings its 

 revenges. Time was, not very long ago, when the belief in 

 creative design was supreme. Even those who were sapping 

 its authority were wont to pay it a formal homage, fearing to 

 shock the public conscience by denying it. Now the revolu- 

 tion is so complete that a great philosopher uses it as a redtictio 

 ad abniriium, and prefers to believe that which can neither be 

 demonstrated in detail, nor imagined, rather than run the 

 slightest risk of such a heresy. 



I quite accept the Professor's dictum that if natural selection 

 is rejected we have no resource but to fall back on the mediate 

 or immediate agency of a principle of design. In Oxford, at 

 least, he will not find that argument is conclusive, nor, I 

 believe, among scientific men in this country generally, how- 

 ever imposing the names of some whom he may claim for that 

 belief. I would rather lean to the conviction that the multi- 

 plying difficulties of the mechanical theory are weakening the 

 influence it once had acquired. I prefer to shelter myself in 

 this matter behind the judgment of the greatest living master 

 of natural science among us. Lord Kelvin, and to quote as my 

 own concluding words the striking language with which he 

 closed his address from this chair more than twenty years ago : 

 " I have always felt," he said, " that the hypothesis of natural 

 selection does not contain the true theory of evolution, if evolution 

 there has been in biology. ... I (eel profoundly convinced 

 that the argument of design has been greatly too much lost 

 sight of in recent zoological speculations. Overpoweringly 

 strong proofs of intelligent and benevolent design lie around 

 us, and if ever perplexities, whether metaphysical or scientific, 

 turn us away from them for a time, they come back upon \is 

 with irresistible force, showing to us through nature the in- 

 fluence of a free will, and teaching us that all living things 

 depend on one everlasting Creator and Ruler." 



SECTION A. 



MATHEMATICS AND PHYSICS. 



Opening Address by Prof. A. W. Rucker, M.A., F.R.S., 

 President of the Section. 



It is impossible for a body of English scientific men to meet 

 in one of our ancient university towns without contrasting the 

 old ideal of the pursuit of learning for its own sake with the 

 modern conception of the organisation of science as part of a 

 pushing business concern. 



We are, as a nation, convinced that education is essential to 

 national success. Our modern universities are w ithin earshot of 

 the whirr of the cotton-mill or the roar of Piccadilly. Oxford 

 and Cambridge themselves are not content to be centres of at- 

 traction to which scholars gravitate. They have devised 

 schemes by which their influence is directly exerted on every 

 market-town and almost on every village in the country. 

 University extension is but a part of the extraordinary multipli- 

 cation of the machinery of education which is going on all 

 around us. The British .\ssociation, which was once regarded 

 as bringing light into dark places, is now welcomed in every 

 large provincial town by a group of well-known men of science ; 

 and we find ready for the meetings of our Sections, not only the 

 chapels and concert-rooms which have so often and so kindly 

 been placed at our disposal, but all the appliances of well- 

 designed lecture-rooms and laboratories. 



I do not propose, however, to detain you this morning with 

 a discourse on the spread of scientific education, but you will 

 forgive me if I illustrate its progress by two facts, not perhaps 

 the most striking which could be selected, but especially appro- 

 priate to our place of meeting. It is little more than thirty 

 years since the two branches of science with which our Section 

 deals, Mathematics and Physics, have been generally recognised 

 as wide enough to require more than one teacher to cope with 

 them in an educational institution of high pretensions and 

 achievement. In i860 the authorities of the Owens College, 

 Manchester, debated whether it was desirable to create a Pro- 

 fessorship of Natural Philosophy in addition to, and inde- 

 pendent of, the Chair of Mathematics. It was thought neces- 

 sary to obtain external support for the opinions of those who 

 advocated this step. An appeal was made to Profs. De Morgan 



