CHANGES IN SCIENTIFIC OPINION 21 



Yet in his later works Lotze seems to have 

 taken up an opposite opinion or to have con- 

 siderably modified his view, since he is de- 

 scribed by McDougall as the " most brilliant 

 and thoroughgoing modern defender " of Ani- 

 mism. Claude Bernard, also, though a vigorous 

 critic of many of the details of the older ideas 

 as to Vitalism, adhered to its main thesis. 



It was not, however, direct writings in critic- 

 ism of the theory which led to the temporary 

 capture of the ancient fortress. Two other 

 theories swept over it and seemed for a time 

 to nave completely destroyed it : with both 

 of which we shall have to deal in subsequent 

 chapters. By far the most important of these 

 was, and is, that of the Conservation of Energy, > 

 foreshadowed by Watt but first formulated by 

 Robert Mayer (1814-1878), who has the credit 

 of being its author, and by Joule. 



Only second to it was the rise of Darwinism. 

 The opinion as to the magnitude of the content 

 of these two doctrines which held the field 

 during the latter part of the nineteenth century 

 is not quite that held to-day, certainly in 

 connection with Darwinism and, in the minds 

 of not a few, with regard to the much more 

 important theory of the Conservation of 

 Enei'gy. 



However, these are matters which must 



