THE SCIENTIFIC IMAGINATION 261 



psychological investigations be made before an ade- 

 quate psychology of scientific discovery can be formu- 

 lated. It may ultimately prove that the passages in 

 which Tyndall and other scientists speak of scientific 

 imagination would read as well if for this term, in- 

 tuition, inspiration, unconscious cerebration, or even 

 reason were substituted. 



At first glance it would seem that the study of the 

 sensory elements of consciousness, motor, tactile, 

 visual, auditory, olfactory, gustatory, thermal, inter- 

 nal, pursued for the last half century by the experi- 

 mental method, would furnish a clue to the nature of 

 the imagination. A visual image, or mental picture, 

 is popularly taken as characteristic of the imaginative 

 process. In fact, the distinguished psychologist Wil- 

 liam James devotes the whole of his interesting 

 chapter on the imagination to the discussion of dif- 

 ferent types of imagery. The sensory elements of 

 consciousness are involved, however, in perception, 

 memory, volition, reason, and sentiment, as they are 

 in imagination. They have been recognized as fun- 

 damental from antiquity. Nothing is in the intellect 

 which was not previously in the senses. To be out of 

 one's senses is to lack the purposive guidance of 

 the intelligence. 



The psychology of individuals and groups shows 

 startling: differences in the kind and vividness of 



o 



imagery. Many cases are on record where the mental 

 life is almost exclusively in visual, in auditory, or in 

 motor terms. One student learns a foreign language 

 by writing out every word and sentence ; another is 

 wholly dependent on hearing them spoken ; a third 

 can recall the printed page with an almost photo- 



