SOURCE: "Kepler's Early Writings," in Journal of the History of Ideas, Vol. XLVI, No. 3, July-September, 1985, 449-54.

Below, Rosen discusses both the background and publication history of two of Kepler's important early writings: Mysterium Cosmographicum, his initial description of the universe, and Apologia, an unfinished manuscript defending Tycho Brahe that was circulated in incomplete form in his day, but was not printed until the nineteenth century.

While teaching school in Graz, Austria, Johannes Kepler (1571-1630) wrote Mysterium cosmographicum, his first major work (Tübingen, 1596). Its printing and publication were supervised by Michael Maestlin (1550-1631), Kepler's former mentor at the University of Tübingen. Having introduced Kepler to Copernicus' astronomy, Maestlin rejoiced that his ex-pupil advocated it openly. But he was somewhat disappointed that in the Mysterium cosmographicum the treatment of some topics was too brief. To remedy this defect, Maestlin, as the editor, might have turned to Copernicus' De...