Dialogo di Galileo Galilei Linceo matematico sopraordinario dello studio di Pisa : e filosofo e matematico primario del serenissimo gr. duca di Toscana doue ne i congressi di quattro giornate si discorre sopra i due massimi sistemi del mondo tolemaico e copernicano: proponendo indeterminatamente le ragioni filosofiche e naturali tanto per l'una quanto per l'altra parte

Florence: Per Gio: Batista Landini, 1632. FIRST EDITION. Hardcover. Fine. Bound in contemporary limp vellum (discreet repair to a tear in the spine). A fine copy with a very rich impression of the frontispiece. A few leaves lightly toned, light damp-stain to outer margin of the first few leaves, marginal 17th c. note on leaf P8, final blank torn. With the added engraved frontispiece depicting Aristotle, Copernicus and Ptolemy discussing the heliocentric and geocentric models of the solar system. A printed correction slip is pasted to the outer margin of page 92, and the letter "H" has been added in manuscript to the diagram on page 192. There is a large woodcut diagram of the heliocentric system, showing Jupiter being orbited by her moons, on page 320. First edition of one of the great landmarks in the history of astronomy: Galileo's validation of the Copernican heliocentric system, for which he was tried before the Inquisition, condemned as a heretic and forced to abjure the theories expressed in this work. "The Dialogo, far more than any work, convinced men of the truth of the Copernican system" (Owen Gingerich).

"Eight years after Pope Paul V had forbidden him to teach Copernican theory, Galileo received permission from a new Pope, Urban VIII, to discuss Copernican astronomy in a book, so long as that book provided equal and impartial discussions of the Church-approved Ptolemaic system. Galileo's 'Dialogue Concerning the Two Chief World Systems' held to the letter of this command: the device of the dialogue, between a spokesman for Copernicus, one for Ptolemy and Aristotle, and an educated layman, allowed Galileo to remain technically uncommitted. After the book's publication, however, Urban took offense at what he felt to be its jibes against himself and ordered Galileo to be brought before the Inquisition in Rome. Galileo was condemned to permanent house arrest and forced to abjure all Copernican 'heresy'" (Norman Library)

Presented as an ostensibly objective discussion between advocates of the Ptolemaic-Aristotelian and the Copernican systems trying to win the support of an educated layman, Galileo's 'Dialogo' displays all the great discoveries in the heavens which the ancients had ignored; it inveighs against the sterility, willfulness, and ignorance of those who defended 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. Astronomy and the science of motion, rightly understood, says Galileo, are hand in glove. There is no need to fear that the earth's rotation will cause it to fly to pieces... The 'Dialogo', far more than any other work, made the heliocentric system a commonplace. If it was not exactly written in defiance of the Inquisition, it was composed with the deliberate intention of bamboozling the censors and of outwitting Galileo's clerical enemies. The censors were the more easy to deceive; after the book was published Galileo's enemies dragged him to Rome in 1633, set him before the Inquisition, and forced him to abjure all that the 'Dialogo' professed... The book itself remained on the 'Index of Prohibited Books' until 1823. (Printing and the Mind of Man 128).