This discussion is followed up concerning the entire system of planets in chapter 2. One of the most important insights provided by this study is that even in pursuing Pythagorean alternatives early modern thinkers remained at the mercy of Aristotle, who provided them with their conceptual and historical means. The complicated debate about the new planet of 1572 gives an opportunity to discuss the nature of mathematics and hypotheses in sixteenth-century astronomy. In insisting that according to the Aristotelian system new stars, and even comets, are beyond nature, and thus miraculous, Bruno does not advocate Galilean mathematics but extends the laws of universal nature beyond the sphere of the moon, a cosmological method that would nevertheless come in handy for the mathematization of nature. Bruno's talking about planets as earths (terre) conceptually paved the way for the discovery of new stars. Johannes Kepler almost always concludes the treatment of an astronomical problem in this book, which creates the expectation that Kepler might be the right key to interpret Bruno, an intriguing suggestion for a further study, which might also address the question when and [End Page 927] where one has to distinguish scientific-astronomical from cosmological-philosophical thoughts.