190 THE CAUSATION OF DISEASE. 



simple mechanical causes {causes efficicntes). Such a mechani- 

 cal explanation is, in the language of Haeckel, " one entirely 

 based on natural science." We are thus able to dispense 

 with designing or teleological causes {finales vausce) . 



We have now to inquire how far the methods by which 

 organic evolution proceeds are severally applicable to man, 

 for whatever pertains to organic evolution may fall within 

 the province of the pathologist, pathology being a branch of 

 biology. 



