332 THE POPULAR SCIENCE MONTHLY 



out. Each book and each, chapter, even, of a book was a separate game 

 with little relation to any other book or chapter or to the world of 

 reality. It was consistent with that part, but had little or no relation 

 to any thing beyond. He never grew up. In consequence he was never 

 burdened by the adult necessity for consistency. Any act or any 

 thought was true for the moment, and that was as far as he was capable 

 of judging. The extent to which writing was a game for him is well 

 illustrated, if we may believe Diderot, by the way he decided to take 

 the most important stand of his life, that against art and science and 

 all departures from nature. Diderot asserts that when Eousseau saw 

 the topic that had been announced by the academy of Dijon in com- 

 petition for a prize " Whether the progress of science and the arts had 

 contributed to corrupt or improve morals," he was on the point of 

 taking sides in favor of the arts and sciences. When, however, Diderot 

 pointed out the advantages of taking the more striking position, he at 

 once accepted it, and the " Discourse upon Science and Arts " was the 

 result. This of course was the key to all of his later writings. It is 

 fair to say that his whole system took its rise in a chance remark, and 

 was the outcome of a desire to attract attention rather than of any 

 high moral purpose. 



As a writer and thinker this mental defect had its points of advan- 

 tage to him. Any thought that occurred to him was given full expres- 

 sion. He need feel no restraint from facts. A half truth was as good 

 as a whole truth, provided only it be picturesque. He could work out a 

 line of thought as in a dream and publish it without feeling the par- 

 alysis of the demand for consistency. When the next thought presented 

 itself he need not reject it because it was incompatible with his last 

 publication. As a psychasthenic he was probably incapable of passing 

 upon the truth or consistency of his ideas. He could believe each in 

 turn with all the fervor of his nature, and work it out to its full logical 

 conclusion with no regard for anything else. 



Eousseau is one of the best instances in support of the theory that 

 genius is allied to insanity. He illustrates at once the strength and the 

 weakness of the insane type of genius. He was full of new and orig- 

 inal ideas that found room to germinate uncontrolled and unchecked by 

 any rational considerations of mutual compatibility and truth. Friend 

 and foe find in these characteristics the basis of adoration and criticism. 

 In the riot of opinion each reader can find what appeals to him. He 

 suits all, as does the phrenologist with his patter. Each can select what 

 seems true to him and overlook or forget the rest. Thus Kant could 

 find in his writings the seeds of his categorical imperative, as truly as 

 the leaders of the Eeign of Terror could find support for their excesses. 

 Pestalozzi drew from him justification for discarding all that was in 

 books, while the literary leaders of the enlightenment were inspired to 



