60 SCIENTIST 



make decisions that have immediate effects that everyone 

 can see. Typically he has to make these decisions right now 

 on the basis of existing knowledge. If he isn't to be para- 

 lyzed to the point of inaction, he must be confident rather 

 than doubtful about the validity of his basic engineering 

 principles. 



Hippocrates, speaking as a physician and not as a medi- 

 cal scientist, described the dilemma of the practical man 

 very well when he began his famous aphorism with the 

 following words: "Life is short and Art is long, the crisis 

 is fleeting, experiment risky, decision difficult." In modem 

 English this might read as follows: "You have to do some- 

 thing right now if this patient is going to get well and you 

 have to do it on the basis of existing knowledge. It takes 

 a long time to make substantial advances in knowledge and 

 it is very dangerous to try something new in the treatment 

 of a particular case." 



A medical scientist would have an entirely different atti- 

 tude. He would be Ukely to say, "It's pretty obvious to me 

 that you really don't know very much about what's wrong 

 with this patient and I doubt that you can do much for him. 

 Why not forget about him for the moment and do some 

 of those experiments which frighten you so much, so that 

 at least the doctors who come after your short life is over 

 will know what they are doing?" 



Clearly we need both sorts of people in the world and 

 it would be fooHsh to ask which is better. It is well worth 

 noting, however, that the practical man's necessary confi- 

 dence in the existing state of his art tends to make him 

 a conservative; or perhaps it is equally valid to say that 

 conservatives tend to become practical men. This attitude 

 goes well beyond their professional life as is demonstrated 

 by the well known political conservatism of the American 



