SCIENTIFIC USE OF THE IMAGINATION. 129 



alty would have been worse than failure. In some fashion 

 or other feebly or strongly, meanly or manfully, on the 

 higher levels of thought, or on the flats of commonplace 

 the task had to be accomplished. I looked in various direc- 

 tions for help and furtherance ; but without me for a time 

 I saw only " antres vast," and within me "deserts idle." 

 >My case resembled that of a sick doctor who had forgotten 

 his art and sorely needed the prescription of a friend. Mr. 

 Bain wrote one for me. He said, " Your present knowl- 

 edge must forge the links of connection between what has 

 been already achieved and what is now required." 3 In 

 these words he admonished me to review the past and re- 

 cover from it the broken ends of former investigations. I 

 tried to do so. Previous to going to Switzerland I had 

 been thinking much of light and heat, of magnetism and 

 electricity, of organic germs, atoms, molecules, spontaneous 

 generation, comets, and skies. With one or another of 

 these I now sought to reform an alliance, and finally suc- 

 ceeded in establishing a kind of cohesion between Thought 

 and Light. The wish grew within me to trace, and to en- 

 able you to trace, some of the more occult operations of 

 this agent. I wished, if possible, to take you behind the 

 drop-scene of the senses, and to show you the hidden mech- 

 anism of optical action. For I take it to be well worth 

 the while of the scientific teacher to take some pains, and 

 even great pains, to make those whom he addresses copart- 

 ners of his thoughts. To clear his own mind in the first place 

 of all haze and vagueness, and then to project into lan- 

 guage which shall leave no mistake as to his meaning 

 which shall leave even his errors naked the definite ideas 

 he has shaped. A great deal is, I think, possible to scien- 

 tific exposition conducted in this way. It is possible, I 

 believe, even before an audience like the present, to un- 

 cover to some extent the unseen things of Nature; and 



1 Induction, p. 422. 



