74 Scientific TrutJi and thc Scientific Spirit 



form of cxcessively minute particles or corpuscles. which were sup- 

 posed to travel with enormous velocity. This " corpuscular " theory 

 in his day and for a hundred years after seemed to explain all the 

 then known phenomena of light. It was not only satisfactory in 

 this respect but it stimulated further inquiry in the siibject. This 

 eventually led to the Promulgation of the " undulatory " theory. 

 according to which light is but a wave motion in the cosmic ether. 

 For the last hundred years this has been accepted as a truth, but 

 in its tum it is failing to explain all new facts as they are ascer- 

 tained. and its acceptance in its original form as a truth may 

 eventually terminate. 



If this is Scientific Truth. what is there to prevent it from 

 running riot. and confusing and misleading rather than guiding? 



The only preventive force is the Scientific Spirit. It is a de- 

 velopment of the quality or tendency of the mind which has com- 

 pelled man in all the periods of his histor}- to discard or to recast his 

 truths because they do not work, and to accept new ones because 

 they do w'ork. That tendency in common life has operated crudely 

 and slowly, it has caused countless mistakes and the temporary ac- 

 ceptance of countless errors. but it has brought us to our presentstage 

 of civilization. It is indeed nothing eise than the pragmatic spirit. 

 The Scientific Spirit is the pragmatic spirit trained in the stricte:;^ 

 fashion to accept only what answers rigid tests and reinforced by 

 an intense curiosity or desire to know. The very essence of this 

 Spirit is manifested in the habit of unceasing, relentless criticism. 

 Without such incessant criticism there would be chaos in Science. 

 The Scientific Spirit, as thus understood. is an all-powerful factor 

 in establishing Scientific Truth. 



To some of you, perhaps to many of you. what I have said may 

 appear as a restatement of a series of truisms, and I am prepared to 

 admit that. I have. however, dwelt on these latters at length be- 

 cause they are of fundamental importance to men of science gen- 

 erally, and, amongst these. to biochemists. especially of the yoimger 

 generation, who have now to meet an extraordinär}- Situation in 

 which these matters are involved. 



A brief sketch of the history of biochemistry to the present date 

 will demonstrate what this Situation is. 



