THE METHOD OF SCIENCE 61 



than one direction. It is rare, for instance, for a capable in- 

 ventor to be a theoretical thinker. Some scientists excel in 

 their ability to visualize general syntheses and thus evolve 

 theories. Some excel in their skill in observation or in their 

 ingenuity in designing experiments. Some have a capacity 

 for inventing and can design entirely new ways of accom- 

 plishing their ends. In addition, certain qualities that are 

 not in any way connected with the scientific mind are, never- 

 theless, of great value in scientific work. In some fields of 

 science, organizing ability is valuable, and men who are 

 outstanding in one of the other factors will be specially quali- 

 fied to use their organizing ability to promote the progress 

 of science. Other qualities of considerable value are clarity 

 of thought and ease of expression, and scientists differ as 

 much in these attributes as do other men. 



Scientists and technologists can advantageously be classified 

 according to the extent to ^vhich they possess the three scien- 

 tific factors and the ability to organize. Descartes, for in- 

 stance, possessed a great power of theoretical synthesis. We 

 have no evidence that he could experiment or that he showed 

 any ability to invent. He probably had no opportunity for 

 organization. Galileo was not only a good theorist but an 

 excellent experimenter, and some of his work suggests that 

 he had considerable ability as an inventor. Newton was out- 

 standing in his capacity for theoretical understanding and as 

 an experimenter. It is improbable that he had any consid- 

 erable talent for invention in spite of his work on the tele- 

 scope and on some other instruments. 



Turning to the moderns, we may compare three great 

 inventors: Lord Kelvin, Thomas Edison, and Elihu Thom- 

 son. Of these, Kelvin was a most capable theorist, an excel- 

 lent experimenter, and an outstanding inventor. There is 

 some reason to believe that he was lacking in capacity for 

 organization, but his distinction in the other three fields 

 makes him one of the greatest scientists of all time. Edison 

 seems to have been purely an inventor. He was not inter- 

 ested in theory, and his experiments were conducted not to 



