272 LIGHT SCIENCE FOR LEISURE HOURS. 



cannot for its life tell whether the paradoxist is a 

 great discoverer or an egregious blunderer. When a 

 paradoxist comes before the world with such statements 

 as generally accompany paradoxy, when he boasts that, 

 without knowing this or that, anything of logic or much 

 of mathematics, he has yet been able to show all the 

 philosophers to be mistaken, then this rule at once 

 disposes of the paradoxist's claim. It is a thing which 

 has never happened for a man without wide and 

 thorough knowledge of a branch of science to make 

 great discoveries in that particular branch ; therefore, 

 the public is not bound to entertain the possibility 

 that the thing has at length happened ; the assertion 

 may be dismissed as incredible. It would be well if 

 this principle were generally known and acted upon ; 

 not well in the interests of the general public, who 

 gain by being puzzled and set a-thinking, but well 

 in the interests of those who desire to spread exact 

 knowledge, and who at present find their labour 

 doubled through the perplexities engendered by the 

 paradoxists. 



Were it not for this necessity of removing the per- 

 plexities of the less instructed, the student of science 

 who hears a paradox propounded might act simply as 

 Sir J. Herschel is said to have done when a paradoxist 

 asserted that he had squared the circle. ' Then,' said 

 Herschel, according to the story, * I wish you a very 

 good morning.' 



That De Morgan partly intended to be of use to 

 those whom paradoxists generally succeed in perplex- 



