Page:Galileo Galilei and the Roman Curia (IA cu31924012301754).pdf/338

 by the sun, and rejects the view advocated by Galileo in his "Sidereus Nuntius," that it arises from a reflection of the sun's rays striking our earth, which the earth reflects to our satellite, who again reflects them to us. Galileo was undecided whether it were not best to take no notice of Liceti's objections, the scientific value of which he did not estimate very highly, when a letter from Prince Leopold de' Medici, brother of the reigning Grand Duke, relieved him of his doubts. This prince, who has gained a permanent name in the history of science by founding the celebrated "Accadémia del Cimento," invited Galileo to give him his views on Liceti's objections. This challenge sufficed to rouse all the blind old man's dialectic skill, though he was then seventy-six and bowed down by mental and bodily sufferings. He dictated a reply, in the form of a letter to Prince Leopold, which occupies fifty large pages in the extant edition of his "Opere," and in fire, spirit, mastery of language, and crushing argument, it is quite a match for the most famous controversial works of his manhood.

A most interesting direct correspondence then ensued between Galileo and Liceti, which was carried on from June, 1640, to January, 1641, in which not this question only was discussed, but Galileo took occasion to express his opinions, with great spirit and learning, on the modern Peripatetic school and philosophy, on Aristotle himself, and his fanatical followers. These letters of the venerable hero of science are characterised by ostensible politeness pervaded by cutting irony, which makes them instructive and stimulating reading.