sect, v.] DISSERTATION SECOND. 



189 



Snellius had never been published, and (he author himself 

 was dead ; but the proposition just referred to had been 

 communicated to his friends, and had been taught by his 

 countryman, Professor Hortensius, in his lectures. There 

 is no doubt, therefore, that the discovery was first made 

 by Snellius, but whether Descartes derived it from him, or 

 was himself the second discoverer, remains undecided. 

 The question is one of those, where a man's conduct in a 

 particular situation can only be rightly interpreted from his 

 general character and behaviour. If Descartes had been 

 uniformly fair and candid in his intercourse with others, 

 one would have rejected with disdain a suspicion of the 

 kind just mentioned. But the truth is, that he appears 

 throughout a jealous and suspicious man, always inclined 

 to depress and conceal the merit of others. In speaking 

 of the inventor of the telescope, he has told minutely all 

 that is due to accident, but has passed carefully over all 

 that proceeded from design, and has incurred the reproach 

 of relating the origin of that instrument, without mention- 

 ing the name of Galileo. In the same manner he omits to 

 speak of the discoveries of Kepler, so qearly connected 

 with his own ; and in twating of the rainbow, he has made 

 no mention of Antonio de Dominis. It is impossible that 

 all this should not produce an unfavourable impression, and 

 hence it is, that even the warmest admirers of Descartes 

 do not pretend that this conduct toward Snellius can be 

 completely justified. 



Descartes would have conceived his philosophy to be 

 disgraced if it had borrowed any general principle from 

 experience, and he therefore derived, or affected to derive, 

 the law of refraction from reasoning or from theory. In 

 this reasoning, there were so many arbitrary suppositions 

 concerning the nature of light, and the action of transparent 



bodies, that no confidence can be placed in the conclusions 



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