August 26, 1904.] 



SCIENCE. 



^5 



trines have been arrived at,— lie will soon 

 be convinced of the exceedingly thin in- 

 tellectual fare which has been hitherto 

 served ont to us under the imposing title 

 of Inductive Theory. 



There is an added emphasis given to 

 these reflections by a train of thought which 

 has long interested me, though I acknowl- 

 edge that it never seems to have interested 

 anyone else. Observe, then, that in order 

 of logic sense-perceptions supply the 

 premises from which we draw all our 

 knoAvledge of the physical world. It is 

 they which tell us there is a physipal world ; 

 it is on their authority that we learn its 

 character. But in order of causation they 

 are effects due (in part) to the constitution 

 of our organs of sense. "What we see de- 

 pends not merely on what there is to be 

 seen, but on our eyes. What we hear de- 

 pends not merely on Avhat there is to hear, 

 but on our ears. Now, eyes and ears, and 

 all the mechanism of perception, have, as 

 we know, been evolved in us and our brute 

 progenitors by the slow operation of nat- 

 ural selection. And what is true of sense- 

 perception is of course also true of the in- 

 tellectual powers which enable us to erect 

 upon the frail and narrow platform which 

 sense-perception provides, the proud fabric 

 of the sciences. 



Now natural selection only works 

 through utility. It encourages aptitudes 

 useful to their possessor or his species in 

 the struggle for existence, and, for a sim- 

 ilar reason, it is apt to discourage useless 

 aptitudes, however interesting they may 

 be from other points of view, because, be- 

 ing useless, they are probably burdensome. 



But it is certain that our powers of sense- 

 perception and of calculation were fully 

 developed ages before they were effectively 

 employed in searching out the secrets of 

 physical reality — for our discoveries in this 

 field are the triumphs but of yesterday. 

 The blind forces of natural selection, 



which so admirably simulate design when 

 they are providing for a present need, 

 possess no power of prevision, and could 

 never, except by accident, have endowed 

 mankind, while in the making, with a 

 physiological or mental outfit adapted to 

 the higher physical investigations. So far 

 as natural science can tell us, every quality 

 of sense or intellect which does not help iis 

 to fight, to eat, and to bring up children, is 

 but a by-product of the qualities which do. 

 Our organs of sense-perception were not 

 given us for purposes of research ; nor was 

 it to aid us in meting out the heavens or 

 dividing the atom that our powers of calcu- 

 lation and analysis were evolved from the 

 rudimentary instincts of the animal. 



It is presumably due to these circum- 

 stances that the beliefs of all mankind 

 about the material surroundings in which 

 it dwells are not only imperfect but funda- 

 mentally wrong. It may seem singular 

 that down to, say, five years ago, our race 

 has, without exception, lived and died in a 

 world of illusions ; and that its illusions, or 

 those with which we are here alone con- 

 cerned, have not been about things remote 

 or abstract, things transcendental or divine, 

 but about what men see and handle, about 

 those 'plain matters of fact' among which 

 common sense daily moves with its most 

 confident step and most self-satisfied smile. 

 Presumably, however, this is either because 

 too direct a vision of physical reality was 

 a hindrance, not a help, in the struggle for 

 existence ; because falsehood was more use- 

 ful than truth; or else because with so 

 imperfect a material as living tissue no 

 better results could be attained. But, if 

 this conclusion be accepted, its consequences 

 extend to other organs of knowledge be- 

 sides those of perception. Not merely the 

 senses, but the intellect, must be judged by 

 it; and it is hard to see why evolution, 

 which has so lamentably failed to produce 

 trustworthy instruments for obtaining the 



