GALILEI, Galileo (1564-1642). Dialogo... sopre i due massimi sistemi del mondo Tolemaico, e Copernicano. Florence: Gian Battista Landini, 1632.
4o (218 x 158 mm). Etched frontispiece by Stefano della Bella, italic type, shoulder notes in roman type, printer's woodcut device on title-page, 31 woodcut illustrations and diagrams in text, woodcut initials, type ornament head- and tail-pieces and factotum initials, errata leaf Ff6, with the printed correction slip pasted in margin of F6v (p. 92) as usual. (Lacks terminal blank, M2, M7 and V8 with lower margins renewed, not affecting text, M4 with small repaired hole in margin, some browning, foxing and occasional marginal paper flaws, some tiny marginal worm tracks.) 19th-century vellum over pasteboard, spine gilt, red and green morocco lettering-pieces.
FIRST EDITION of Galileo's celebrated defense of the Copernican view of the solar system. In 1624, eight years after Pope Paul V had forbidden him to teach the Copernican theory, Galileo was given the chance to express these views by the new Pope, Urban VIII (Maffeo Barberini, 1568-1644), his friend, admirer and patron for more than a decade. The Pope gave Galileo permission to write a book about theories of the universe, "provided that the arguments for the Ptolemaic view were given an equal and impartial discussion" (DSB). His Dialogo was finished in 1630, and Galileo sent it to the Roman censor. Because of an outbreak of the plague, communications between Florence and Rome were interrupted, and Galileo asked for the censoring to be done instead in Florence. The Roman censor had a number of serious objections to the book and forwarded these to Florence. After writing a preface which claimed that what followed was written hypothetically, Galileo had little trouble getting the book through the Florentine censors.
Galileo's formal use of the dialogue allowed him to explore his Copernican theories fully within the rubric of the "equal and impartial discussion" required by the Pope. The three protagonists are Salviati, an advocate of the Copernican theory, Simplicio, an upholder of the Ptolemaic orthodoxy (and generally interpreted as representing Pope Urban VIII) and Sagredo, an impartial educated layman. The work "was designed both as an appeal to the great public and as an escape from silence... it is a masterly polemic for the new science. It displays all the great discoveries in the heavens which the ancients had ignored; it inveighs against the sterility, willfulness, and ignorance of those who defend their systems; it revels in the simplicity of Copernican thought and, above all, it teaches that the movement of the earth makes sense in philosophy, that is, in physics... The Dialogo, more than any other work, made the heliocentric system a commonplace" (PMM). Pope Urban VIII was not swayed, and immediately convened a special commission to examine the book and make recommendations. In casting the Pope as the simple-minded Aristotelian Simplicius, Galileo brought upon himself arrest, trial by the Inquisition and life imprisonment. The sentence was commuted to permanent house arrest, but the printing of any of his works was forbidden. The Dialogo remained on the Index until 1832.
Carli and Favaro, p.28; Cinti 89; Dibner Heralds of Science 8; Grolier/Horblit 18c; Norman 858; PMM 128; Wellcome 2647a.