Page:Galileo Galilei and the Roman Curia (IA cu31924012301754).pdf/163



is a curious fact that the very work which was destined to be one of the most powerful levers in obtaining general recognition for the true order of the universe originated in what we now know to be an erroneous idea. The famous book, "Dialogues on the Two Principal Systems of the World, the Ptolemaic and Copernican," arose out of the treatise on the tides which Galileo wrote at Rome, in 1616, at the suggestion of Cardinal Orsini. The important influence of these "Dialogues," both on science and the subsequent fate of the author, obliges us to discuss them more particularly.

The book contains a great deal more than is promised by the title; for the author included in it, in connection with the discussion of the two systems, nearly all the results of his researches and discoveries in science, extending over nearly fifty years. He also endeavoured to write in a style which