LIFE AND WORKS OF KEPLER. 95 



bingen, he was not thought qualified to labor for the advancement of 

 the church, and, furnished onlywith a flattering attestation of eloquence 

 and capacity, he \vas named professor of mathematics and morals in the 

 college of Oriitz, in Styria. 



The Archduke Charles, of Austria, who then goverued Styria, pro- 

 fessed the Catholic religion ; but, what was very rare and little to be 

 expected at that epoch, he extended to heretics an absolute tolerance ; 

 so that the Protestants, who then constituted a majority of the rich and 

 enlightened classes, enjoyed full liberty to call to their service for all 

 offices such of their co-religionists as had been instructed elsewhere. 

 Hence it was, that Kepler received an invitation to Griitz. Instruction 

 in astronomy being one of his duties, he was charged witli the compila- 

 tion of an almanac, and it was but natural that in a Catholic country, 

 he should adopt the Gregorian reform which the Protestants obstinately 

 rejected ; choosing much rather, as was said, to be at variance with the 

 sun than in accordance with the Pope. Kepler, who never consented under 

 the most difficult circumstances to compound for the free expression of his 

 religious sentiments, separated, on this occasion, from his co-religion- 

 ists ; the question, as he justly urged, was a purely scientific one. More 

 than once in his career did he encounter it, and his opinion never varied. 

 Sixteen years later, in 1013, in order to induce Germany to accept the 

 new calendar, he composed, at the instance of the Emperor Matthias, a 

 dialogue between two Catholics, two Protestants, and a niathematician, 

 the latter of whom enlightens, and finally convinces the others ; but 

 Kepler was not equally successful with the Diet, to which the question 

 was submitted, and, in spite of his efforts, the Gregorian reform was 

 postponed till a long time afterward. 



To increase the sale of his almanacs, Kepler did not shrink from in- 

 serting astrological predictions of political and other events, and, as a 

 few hajjpened to be realized nearly at the time predicted, not a little 

 credit accrued to him on that account. His biographers have affirmed, 

 however, that, superior to the prejudices of his age, he had no faith in 

 astrological divination, but his correspondence shows that at this epoch, 

 and even many years afterward, he was persuaded of the influence of 

 the stars on events of every nature. In one of his letters he makes an 

 applicatio nof his principles to the newly-born son of his master, Moest- 

 lin, and announces that he is threatened with a great danger. " I doubt," 

 he says, "whether he can survive it;" and, in fact, the child died. Just 

 at that time one of his own children was also taken away; and when, 

 on occasion of this double bereavement, we find him, with expressions 

 of afi'ectionate interest for his master, again speaking of the fears which 

 he had conceived, how is it possible to believe that he was not in earnest? 

 But his predictions were not always so exactlj^ fulfilled, and, after being 

 often deceived, Kepler became less and less credulous. Thus it fared 

 with astrology as with many other errors which entered his mind with- 

 out taking root. He said, indeed, that, as the daughter of astronomy, 

 astrology ought to nourish her mother; and he continued during life 

 to make for those who asked it, and for a consideration, predictions and 

 horoscopes conformable to the rules of the art. But, so far from abusing 

 the credulity of his clients, he avowed to them that, in his oi)inion, his 

 conclusions should be regarded as uncertain and suspicious; telling 

 them, as Tiresias tells Ulysses, (in Horace:) Quicqiiid dicam aut eritaut 

 non — (What I may say will or will not come to pass.) 



The first scientific work of Kepler is entitled Mysterium cosmof/mphi- 

 cum, and was composed during the earlier part of his residence at Griitz. 



I undertake to prove," he says in his preface, " that God, in creating 



