Kepler's Attitude Toward Pico and the Anti-astrology Polemic*

In two of his major works,On the New Star(1606) andHarmonics of the Universe(1619), Johannes Kepler engaged in an extensive debate against Giovanni Pico della Mirandola'sDisputations against Judicial Astrology.But despite his disagreements with Pico'sDisputations, Kepler wrote about it in these works with deep respect and even expressed many points of agreement with it. Ernst Cassirer suggested that despite Kepler's continuing practice and support of astrology, Kepler essentially adopted Pico's idea of the human being making himself and thus gradually liberated himself from a belief in astrological determinism: “The problem of freedom is closely allied to the problem of knowledge; the conception of freedom determines that of knowledge, just as, conversely, the latter determines the former. The spontaneity and productivity of knowledge finally become the seal of the conviction of human freedom and human creativity.”