Dialogue Concerning the Two Chief World Systems: Ptolemaic and Copernican

Galileo’s Dialogue Concerning the Two Chief World Systems, published in Florence in 1632, was the most proximate cause of his being brought to trial before the Inquisition. Using the dialogue form, a genre common in classical philosophical works, Galileo masterfully demonstrates the truth of the Copernican system over the Ptolemaic one, proving, for the first time, that the earth revolves around the sun. Its influence is incalculable. The Dialogue is not only one of the most important scientific treatises ever written, but a work of supreme clarity and accessibility, remaining as readable now as when it was first published. This edition uses the definitive text established by the University of California Press, in Stillman Drake’s translation, and includes a Foreword by Albert Einstein and a new Introduction by J. L. Heilbron.

J. L. Heilbron is a professor of history and Vice Chancellor Emeritus, University of California at Berkeley, and currently Senior Research Fellow, Worcester College, Oxford. He is the author of numerous books on the history of science, including most recently The Sun in the Church: Cathedrals as Solar Observatories and Geometry Civilized: History, Culture, and Technique.

Stephen Jay Gould is the Alexander Agassiz professor of zoology and professor of geology at Harvard and the Vincent Astor visiting professor of biology at New York University. Recent books include Full House, Dinosaur in a Haystack, and Questioning the Millennium. He lives in Cambridge, Massachusetts, and New York City.