xii ACTIVITY AND SUBSTANCE 223 



have anticipated the scientists. Berkeley, arguing from 

 the current notion of Substance, had the genius to per 

 ceive that material substance was a philosophic super 

 fluity. Hume promptly extended this argument to the 

 destruction of spiritual substance. He pointed out that 

 apart from its states there was no self or soul. So he 

 resolved the self into the sequence of its states of con 

 sciousness. 1 



Both Berkeley and Hume were fully justified in their 

 criticism. How right they were the sciences proceeded 

 to discover on their own account. In the last thirty years 

 it has become quite a commonplace in psychology to 

 proclaim soul-substance useless, and to conceive the 

 mind as consisting of a stream of consciousness. And 

 at the present moment physicists seem to be finally 

 making up their minds that the matter which had 

 lingered on in physics as the substrate of physical pheno 

 mena is mere scaffolding, and that all scientific facts 

 can really be more simply and conveniently conceived as 

 transformations of energy. Now it would not yet be 

 true to say that the conception of Energy in modern 

 science coincides with the ancient conception of Energeia. 

 But they agree in rejecting the old notion of substance 

 as a substratum. It is clear, moreover, that they are 

 akin in spirit, and that in the hands of a master like 

 Prof. Ostwald 2 the conception of energy is rapidly 

 approximating to that of Energeia. Indeed the chief 

 difference at present is that whereas Energeia avowedly 

 and consciously stands for a theory of substance, Energy 

 still seems to crave for a backbone of substantiality. 

 Thus the scientific auguries seem favourable to a reform 

 of the conception, while an inveterate error may well be 

 judged to be decrepit when its patrons discover it to be 

 of no avail. 



Alike in philosophic and in scientific circles then, it 



1 J. S. Mill similarly sees that Substance is only postulated as a support for 

 phenomena, and that if we think away the support and suppose the phenomena 

 to remain without any agency but an internal law, every consequence, for the sake 

 of which Substance was assumed, will follow without Substance. Exam, of 

 Hamilton, p. 252. 



2 See his admirable treatise on Naturphilosophie. 



