180 THE PRINCIPLES OF SCIENCE 



In speaking here concerning "comprehensibility," the expression is 

 used in its most modest sense. It imphes: the production of some sort 

 of order among sense impressions, this order being produced by the 

 creation of general concepts, relations between these concepts, and by 

 [various determinate] relations between the concepts and sense experi- 

 ence. ... It is in this sense that the world of our sense experiences 

 is comprehensible. The fact that it is comprehensible is a miracle. 



The "miracle" can, of course, be taken in various ways. Edelstein 

 writes in a somewhat Kantian vein that: 



On the basis of the hypothesis that the world can be understood by 

 reason some men in Ionia in the early 6th century created a world that 

 reason understands. 



Here congruence would arise from "construction" of the world by 

 mind. Galileo thought diflFerently, rejecting the view that: 



. . . Nature had first made men's brains and then disposed all things 

 in conformity to the capacity of their intellects. But I incline rather to 

 think that Nature first made the things themselves, as she best liked, 

 and afterwards framed the reason of man capable of conceiving 

 (though not without great pains) some part of her secrets. 



Today we incline very strongly to Galileo's opinion, thinking to have 

 found, in the theory of evolution by natural selection, a mechanism 

 competent so to have "framed the reason of man." By that mechanism 

 Einstein's miracle is toppled into a class with so many others that once 

 loomed large in the argument from design. Hear Sherrington: 



Our stock is the vertebrate stock; our body is the vertebrate body; our 

 mind is the vertebrate mind. If the vertebrates be a product of the 

 planet, our mind is a product of the planet. Its activities and pro- 

 clivities declare it so. Its senses each and all gear into the ways and 

 means of our planet which is its planet. They are adapted to it, as a 

 fish's bodv to water. . . . Ours is an earthlv mind which fits our 

 earthly body. It produces percepts of earthly things from an earthly 

 viewpoint. It helps the besouled body to deal with terrestrial things, 

 thereby to live. Our mind constructs "time" and its time's rate is that 

 of its besouled body's terrestrial habitat; although it, not unnaturally, 

 has supposed it to be an universal and absolute Time. The last pre- 

 ceding turn of its planet is its "yesterday" and the next expected turn 

 will be its "tomorrow," . . . 



. . . We are, in biological phrase, reactions. The situation creates 



