Harmonikale Kosmologie: Johannes Kepler und Athanasius Kircher; Harmonikale Kosmologie: Johannes Kepler und Athanasius Kircher; Harmonical cosmology: Johannes Kepler and Athanasius Kircher.

The connection between musical theory and astronomy is an aspect of Pythagorean cosmology, which still played a role in the 17th century, and was advanced at that time in very different ways: while Johannes Kepler conceives a proper geometrical system of harmonics and tries to connect it with accurate astronomical data, Athanasius Kircher, harshly criticising Kepler's ideas, sets a qualitative system against it, which is based on analogies. The reason for this discrepancy is not only found in the basically different systems of harmonics of both researchers, but also in the different positions that were taken by both within the controversy about the heliocentric system of the world.