THE DOCTRINE OF ENERGY 83 



have been taught and have always maintained 

 that Matter is the direct object of sense-perception. 

 No doubt it is long since Philosophy has urged 

 that our conceptions of the external world are 

 a mentally constructed system. But this doctrine 

 has made but little impression upon the students 

 of Natural Science. The objective origin of our 

 sensations and the apparently objective reality 

 also of the intelligible qualities and operative laws 

 of the external world are too strongly impressed 

 upon their minds. Idealism and Transcendentalism 

 have carried no conviction to them. Still, the 

 difficulties of common sense have continued to 

 grow. Recent developments of scientific theory 

 have increased the urgency of the problem, but they 

 seem to us also to suggest a solution the beneficial 

 results of which affect the whole of Metaphysics. 



We refer to the doctrine of Energy, which occupies 

 now as great a place in the physical sciences as the 

 doctrine of Evolution does in the zoological sciences. 



Natural philosophers have for some time taught 

 that there are two Real Things in the physical 

 ''universe Matter and Energy. It seems a very 

 striking theory. Has it received the attention 

 it deserves from the student of Metaphysics ? We 

 are convinced that it has not : and the reason 

 he most frequently gives for this neglect is that, 



