224 BACTERIOLOGY. 



and Virchow, who recognized more clearly 

 than their predecessors that disease, as well as 

 normal life, is a process. A process, a me- 

 chanical or dynamical process, cannot, how- 

 ever, be a living entity ; and hence Lotze and 

 Virchow struck a fatal blow at the unscientific 

 notion of a disease essence. Something in 

 addition to this notion, however, dwelt in the 

 conception of Sydenham, namely the observa- 

 tion that the " specific " disease must have a 

 cause, although he did not separate sufficiently 

 the conception of a predisposition to disease 

 from that of the cause of disease. He recog- 

 nized further that the character of the specific 

 infectious disease varies greatly in different 

 epidemics, and attributed this variation to the 

 genius epidemicus, without remarking that the 

 term expressed a fundamental departure from 

 his conception of rigid disease types. 



From the manifest opposition between Syd- 

 enham's conception of a " disease species " as 

 an entity, and Lotze and Virchow's conception 

 of disease as a process, we are able at once to 

 understand Virchow's direct and vigorous op- 

 position to those bacteriologists who still stick 

 fast in the fetters of ontology, and for whom 

 disease-producing bacteria are only mystical 

 entities which they would like to set in the 

 place of the older personifications of priestcraft 



