286 



SCIENCE 



[N. S. Voi,. XXXVII. No. 947 



dogmatic statements as to what is intrinsic- 

 ally possible or forever impossible, for the 

 endeavors of human knowledge. Have we 

 not been told that the distances of the fixed 

 stars could never be measured; that the 

 achromatism of lenses could not be carried 

 beyond a certain point, which has already 

 been considerably surpassed; that steam- 

 ships could never cross the ocean and air- 

 ships never sail the air, in safety; that 

 synthetic chemistry in the laboratory could 

 never simulate the products of animal and 

 vegetable organisms ; that the speed of the 

 nerve current could never be measured, 

 etc., etc. 



But what does all this purely empirical 

 way of fixing the limitations of science 

 amount to in the respect of justifying our 

 attempts to regulate the hopeless waste of 

 man's endeavors to know the forever un- 

 knowable? Even to-day we may be just 

 as ignorantly — with an ignorance even 

 made more exasperating by the fact that 

 it is so often the outgrowth of our conceit 

 of knowledge— denying the alleged facts 

 of telepathy as was Newton when he re- 

 fused to explain gravitation as actio dis- 

 tans. But whether this or that particular 

 prediction come true or not, this is not the 

 point. The point is this : that by the study 

 of man we are able to fix certain limita- 

 tions to all science which are inherent in 

 the very nature of man himself and in his 

 relations to that larger nature of which he 

 is a part. It is to the consideration of 

 this sort of limitations that we now devote 

 a moment's attention. 



That the senses, from the nature of the 

 psychophysical organism which they serve, 

 are limited in capacitJ^ is a matter of 

 course. Their anatomical structure and 

 their forms of functioning, physiologically 

 considered, require that the range and ac- 

 curacy of their observation should be con- 

 fined within certain limits, both of space 



and of time. In the eye, the size of the 

 rods and cones; in the ear, the physical 

 construction of the bony and muscular 

 parts of the cochlea; in the skin, the fre- 

 quency and arrangement of the tempera- 

 ture spots and the pressure spots — all these 

 special limitations of the organism are lim- 

 its to the measuring power of human sense- 

 perception. Let these physical limitations 

 be changed, either in the direction of im- 

 provement or of depreciation, and there 

 would still be similar limitations inherent 

 in the organic structure of the race, and 

 varying with different individual members 

 of the race. In all the various realms of 

 sense-perception, there will always be that 

 which lies beyond, and which can only be 

 conjectured, or at best reasonably inferred, 

 but which can never become immediately 

 perceived by human senses. Surrounding 

 the expanding island of the visible world 

 will be the boundless sea of the invisible; 

 of that which can be touched and handled, 

 the many things that no skin is sensitive 

 enough to feel and that no hand can grasp. 



These limitations of the senses set their 

 limitations to the pictorial imagination, or 

 imaging faculty, as distinguished from 

 what logicians have been accustomed to call 

 "pure thought." How things would look, 

 the like of which no eye has ever seen; 

 how things would sound, the like of which 

 no ear has ever heard, will remain ques- 

 tions to which the experience of measuring 

 all things with the senses can give no 

 answer. 



But there are other irremovable limita- 

 tions to human knowledge which are even 

 more important, although more difficult to 

 make obvious. These are limitations in- 

 herent in the very constitution of the intel- 

 lectual powers. The intelligence of man 

 has its own way of working, its laws of 

 behavior, its inescapable modes of opera- 

 tion, to whatever subject it may be applied. 



