130 PSYCHOLOGY, 



consistently physiological point of view, that it is quite 

 wonderful to see how late it was stumbled on in philosophy, 

 and how few people, even when it has been explained to 

 them, fully and easily realize its import. Much of the 

 polemic writing against it is by men who have as yet failed 

 to take it into their imaginations. Since this has been the 

 case, it seems worth while to devote a few more words to 

 making it plausible, before criticising it ourselves. 



To Descartes belongs the credit of having first been bold 

 enough to conceive of a completely self-sufficing nervous 

 mechanism which should be able to perform complicated 

 and apparently intelligent acts. By a singularly arbitrary 

 restriction, however, Descartes stopped short at man, and 

 while contending that in beasts the nervous machinery was 

 all, he held that the higher acts of man were the result 

 of the agency of his rational soul. The opinion that 

 beasts have no consciousness at all was of course too para- 

 doxical to maintain itself long as anj'thing more than a 

 curious item in the histor}^ of philosophy. And with its 

 abandonment the very notion that the nervous system per se 

 might work the work of intelligence, which was an integral, 

 though detachable part of the whole theory, seemed also to 

 slip out of men's conception, until, in this century, the 

 elaboration of the doctrine of reflex action made it jDossible 

 and natural that it should again arise. But it was not till 

 1870, I believe, that Mr. Hodgson made the decisive step, 

 by saying that feelings, no matter how intense!}' they may 

 be present, can have no causal efficacy whatever, and com- 

 paring them to the colors laid on the surface of a mosaic, of 

 which the events in the nervous system are represented by 

 the stones.* Obviously the stones are held in place by each 

 other and not by the several colors which the}' support. 



About the same time Mr. Spalding, and a little later 

 Messrs. Huxley and Clifford, gave great publicity to an 

 identical doctrine, though in their case it was backed by 

 less refined metaphysical consideration s.f 



* The Theory of Practice, vol. i, p. 416 ff. 



f The present writer recalls how iu 1869, when still a medical student, 

 he began to write an essay showing how almost every one who speculatea 

 about brain-processes Illicitly interpolated into his account of them liai s 



