GALILEO GALILEI 37 



sides like the moon, and that many small stars made up the Milky 

 Way. 



In 1610 he left Padua for Florence, and by 161^ openly declared 

 his acceptance of Copernican ideas. Immediately he was opposed 

 by theologians, and after -being given an opportunity to renounce 

 his adherence to the new system of astronomy, was sentenced in 

 ]i6i6 not to hold, teach, or defend it. In 162^, when his friend Maf- 

 feo was made Pope Urban VIII, he wrote his dialogues on the system 

 of the world. He had much difficulty in getting them published and 

 succeeded only when he assured the authorities that they were not 

 heretical. It was quite evident, however, that the dialogues were 

 slightly concealed arguments for the acceptance of the Copernican 

 system and consequently in 16^^ he was summoned before the Inqui- 

 sition and compelled to renounce his heresy. In 1637, a few months 

 after he had discovered the librations of the moon, he lost his sight. 

 He died five years later, January 8, 1642. 



THE COPERNICAN VERSUS THE PTOLEMAIC 



ASTRONOMIES * 



Formerly I used frequently to visit the marvelous city of Venice 

 and to meet there Signore Giovan Francesco Sagredo, a man of most 

 distinguished ancestry and remarkable intelligence. Thither also came 

 from Florence, Signore Filippo Salviati, whose least claim to renown 

 was his noble blood and great wealth; a noble mind, that held no 

 enjoyment of greater price than that of study and thought. With 

 both of these men I often discussed these questions, in the presence 

 of a Peripatetic philosopher, who apparently valued the acquisition of 

 knowledge in no way in so high a degree, as he did the renown which 

 his interpretations of Aristotle had gained for him. 



Now that cruel death has robbed the cities of Venice and Florence 

 of these two enlightened men in the bloom of their years, I have 

 endeavored, as far as my weak powers may permit, to perpetuate 

 their fame in these pages by making them the speakers in this dialogue. 

 The valiant Peripatetic also shall not fail to appear; because of his 

 over-weaning love for the commentary of Simplicius, it seemed 

 permissible to omit his own name and let him pass under that of his 

 favorite author. May the souls of these two great men accept this 



* Translated from the Dialogo dei due Massima Systemi del Hondo (1632). 



