PREFACE. Vll 



Cardan is determined to hide nothing, and it is not less 

 evident that he has been ill-rewarded for his frankness. 

 Over and over again all self-accusations have been accepted 

 and driven home against him, all self-praise has been called 

 vanity, and statements of his that appeared to be too 

 marvellous have been pronounced untrue. 



But the man of profound genius sometimes wrote, we 

 are told, as if he were a fool. His folly may instruct us. 

 It belonged bating some eccentricities not to himself 

 alone. His age claimed part in it, and bought his books. 

 He was the most successful scientific author of his time; 

 the books of his that were most frequently reprinted 

 being precisely those in which the folly most abounded. 

 He was not only the popular philosopher, but also the 

 fashionable physician of the sixteenth century. Pope and 

 emperor sought him; kings, princes, cardinals, arch- 

 bishops were among his patients. There were other 

 physicians in those days wise enough to be less credulous 

 on many points, but greater wisdom did not win for them 

 an equal fame. Cardan obtained a splendid reputation 

 wholly by his own exertions, not only because he was a 

 man of power and genius, but because he spent much of 

 his energy upon ideas that, foolish as they now seem, 

 were conceived in the true spirit of his age. He belonged 



