Johannes Keplers Dioptrik, oder Schilderung der Folgen, die sich aus der unlängst gemachten Erfindung der Fernrohre für das Sehen und die sichtbaren Gegenstände ergeben. Übersetzt und herausgegeben von Ferdinand Plehn

Born of a mother who was often accused of being a witch, Kepler was a sickly child, but went on to survive the deaths of his wife and three children. An astronomer probably more by proclivity than by choice, Kepler had always longed to be a theologian. Enrolled in theology at the German University of Tübingen, he became a staunch advocate of Copernicus' astronomy. His mathematical ability was well-known among many professors; and it soon earned him a mathematical post in Graz. Later in Prague, when his boss and mentor Tycho passed away, he was the obvious choice to become his successor. Finally, although Kepler openly honored and respected the work of Galileo (see Starry Messenger), he would never receive the same accolade from Galileo in return.