Dialogo. Matematico Sopraordinario, 1632. Dove ne i congressi di quattro giornate si discorre sopra i due massimi sistemi del mondo Tolemaico, e Copernicano. Florence: Batista Landini, 1632. First edition of this epoch-making event, Galileo's historic defense of the Copernican view of the solar system, the most notoriously fateful, the most notoriously banned book of the 17th century. EPPUR SI MUOVE. First edition of the work that led to Galileo's persecution by the Inquisition, with 31 in-text woodcut illustrations and diagrams. An extremely good copy bound in later 1/2 vellum over decorative paper boards, title on spine in gilt.

Although the Copernican theory that the planets revolve around the sun had been formally declared heretical in 1616, Galileo presumed to defend it again, as his old friend, Maffeo Barberini, was elevated to the papacy, Pope Urban VIII in 1623. Urban granted Galileo permission -- "so long as the 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" (Norman, 858).

In 1633, less than a year following its original appearance, the Inquisition suppressed Galileo s book. Few survive.

"Such a mind may be hampered by others; it may be silenced, proscribed, imprisoned or destroyed; it cannot be forced. A gun is not an argument.... It is from the work and the inviolate integrity of such minds -- from the intransigent innovators -- that all of mankind s knowledge and achievements have come. (See The Fountainhead.)" (Rand, 9).

Dialogo remained on the Index Librorum Prohibitorum until 1832. Galileo's first publications enjoyed little circulation. "The Dialogo was designed both as an appeal to the great public and as an escape from silence. In the form of an open discussion between three friends intellectually speaking -- a radical, a conservative, and an agnostic -- it is a masterly polemic for the new science. So Galileo picked up one thread that led straight to Newton. The Dialogo, far more than any other work, made the heliocentric system a commonplace. Every fear of Galileo's enemies was justified; only their attempts to stifle thought were vain" (PMM, 128).

Complete with final blank present (2K4); the cancel slip is present on page 92. Vellum toned and soiled, front board with stain and chip, some loss to edges at corners. Early ink inscription to title, title with printing error filled in with early manuscript and one small paper repair. Approximately first 45 pages with a worm-track near upper margin (larger at front, dissipating thereafter, to lower inner corner, not affecting text). leaf L8 with small marginal note in early ink, two leaves with short closed marginal tears; almost all pages clean. Book #BB1v251. $100,000. From a private collection of the choicest, finest rare books in exemplary condition: Bill's "Circle of Thought."