Published online by Cambridge University Press: 20 November 2018
In two of his major works, On the New Star (1606) and Harmonics of the Universe (1619), Johannes Kepler engaged in an extensive debate against Giovanni Pico della Mirandola's Disputations against Judicial Astrology. But despite his disagreements with Pico's Disputations, 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.”
A version of this paper was read at the Columbia University Renaissance Seminar, 3 December 1991. I am grateful to Professors Wilbur Applebaum, Mary Ellen Bowden, Paul Oskar Kristeller, Fred J. Nichols, and Robert S. Westman and to Dr. Alan Weissman for their comments on earlier drafts of this paper. The anonymous readers for Renaissance Quarterly also offered insightful criticisms. Some of the material in this paper comes from my dissertation, and I would like to thank my advisors, Professors Richard Lemay and the late Edward Rosen, and my readers, Professors Joseph W. Dauben, Frank D. Grande, and Nancy G. Siraisi for their suggestions and corrections.