July 21, 1916] 



SCIENCE 



89 



of the "external" world must be acquired 

 through the senses, i. e., through the physio- 

 logical-psychological process. This process 

 involves three steps: (1) The stimulus (the 

 object in the external world) ; (2) The 

 nerve disturbance (caused by the stimulus) ; 

 (3) The sensation or sense impression (the 

 result of the nerve disturbance). Through 

 the discoveries of the chemist and the physi- 

 cist he learns that all of the phenomena of 

 the external world may be reduced to or 

 expressed in terms of atoms or electrons in 

 motion, rapidly in gases, less so in liquids 

 and still less so in solids; that all chemical 

 change involves a rearrangement of atoms, 

 and finally that all forms of energy depend 

 on the rapid movement of atoms. More- 

 over, the physiologist assures him that 

 these assertions hold true for the living as 

 well as for the lifeless. Thus the physical 

 (external) universe appears to be a uni- 

 verse of atoms or electrons in motion. 



Up to this point in his thinking our hy- 

 pothetical friend has been standing on per- 

 fectly sound ice. With his conclusion there 

 is not the slightest reason to disagree. This 

 — the mechanistic interpretation of the 

 physical universe — is the accepted interpre- 

 tation of our generation. Its validity as a 

 scientific hypothesis stands unchallenged. 

 There is no reason whatever to believe that 

 in principle it will ever be overthrown. 

 The mechanist gets on very thin and very 

 treacherous ice (where the philosopher is 

 unable to follow him) when he infers that 

 when electrons come together in certain 

 propositions and under certain conditions 

 consciousness would be the result. Thus he 

 might reach the conclusion of the material- 

 ist that whether there were any conscious- 

 ness at all, the dance of atoms and the mate- 

 rial universe would go on just the same. 

 The universe, then, he concludes, is in real- 

 ity a universe of atoms and electrons inde- 

 pendent of consciousness. Some such proc- 



ess of reasoning as this appears to be the 

 usual method of the transformation of the 

 mechanistic thinker into a materialistic 

 philosopher. The considerations which ap- 

 pear to invalidate his conclusion have al- 

 ready been stated above. 



The disproof of materialism (as a philos- 

 ophy — not as a working scientific hypoth- 

 esis) is at the same time the argument ad- 

 duced in support of philosophical idealism 

 (spiritualism), the status of which is so 

 unquestioned that it has become the domi- 

 nant philosophy of the twentieth century. 

 Many scientific investigators impressed by 

 its logical soundness have adopted it as the 

 basis of their thought and of their interpre- 

 tation of nature and of life. 



That the world of science is withal a 

 world of ideas has been appreciated by 

 scientific thinkers scarcely less than by 

 philosophers. "Our one certainty is the 

 existence of the mental world," writes 

 Huxley. "Ego is the only reality and 

 everything else is only Ego's idea," says 

 Charles Sedgwick Minot. "The sole real- 

 ity that we are able to discover in the world 

 is mind," says Verworn. "Our world is 

 after all a world of individual conscious- 

 ness and ideas," says Crampton. "The 

 field of science is essentially the contents of 

 the mind, ' ' says Karl Pearson. ' ' The world 

 of knowledge is of such stuff as ideas are 

 made of," writes Josiah Royce. 



Thus the basis of modern critical ideal- 

 ism is so sound that its position has come to 

 be regarded as impregnable, and the argu- 

 ments now used against it are not directed 

 at its foundations, but at certain supposed 

 logical consequences of its acceptance. 

 Many of the arguments raised against crit- 

 ical idealism are based on misunderstand- 

 ing. One of these is the erroneous inference 

 that idealism is subversive of a mechanistic 

 interpretation of the physical universe. To 

 hear some of the arguments used against it 



