214 ON THOUGHT IN MEDICINE. 



tolerance partly against each other, and partly against 

 the eclectics who found various explanations for various 

 forms of disease. This method, which in its essence is 

 completely justified, had, in the eyes of systematists, 

 the defect of being illogical. And yet the greatest 

 physicians and observers, Hippokrates at the head, 

 Aretaeus, Galen, Sydenham, and Boerhaave, had become 

 eclectics, or at any rate very lax systematists. 



About the time when we seniors commenced the 

 study of medicine, it was still under the influence of 

 the important discoveries which Albrecht von Haller had 

 made on the excitability of nerves ; and which he had 

 placed in connection with the vitalistic theory of the 

 nature of life. Haller had observed the excitability in 

 the nerves and muscles of amputated members. The 

 most surprising thing to him was, that the most varied 

 external actions, mechanical, chemical, thermal, to 

 which electrical ones were subsequently added, had 

 always the same result; namely, that they produced 

 muscular contraction. They were only quantitatively 

 distinguished as regards their action on the organism, 

 that is, only by the strength of the excitation; he 

 designated them by the common name of stimulus ; 

 he called the altered condition of the nerve the exci- 

 tation, and its capacity of responding to a stimulus 

 the excitability, which was lost at death. This entire 

 condition of things, which physically speaking asserts 



