Ehrlich

“Where would matters end if, in diseases which were not of a vitally dangerous nature, the surgeon were permitted to undertake only such operations as were absolutely free from risk? An irrational restriction of this kind would halt the marvelous development of surgery at a stroke. The surgeon works with a steel knife, the chemotherapist with a chemical one which he uses to separate the morbid from the healthy. It is clear that there can be no difference between the therapeutic ethic of the physician and that of the surgeon. And if such a difference does actually exist, it rests only on the notion that medicine should do no harm, whereas everyone knows that an operation always entails certain risks” (from his The Experimental Chemotherapy of Spirilloses [1910], quoted in Bäumler, 180).