In this article, I address the epistemological role that geometry plays in Kepler’s Harmonices Mundi Libri V and argue that the framework he develops there is meant to address concerns regarding the confirmation of astronomical hypotheses, which are supported by comments in earlier works regarding empirical underdetermination. The geometrical epistemology that he constructs to combat these concerns in the Harmonices Mundi is introduced in Book I and then is extended to his theory of harmonic proportion in Book III, finally providing (...) the foundation for his derivation of the planetary motions in Book V. To argue for these claims, I begin by discussing Kepler’s concern with underdetermination in earlier works. Then I turn to the Harmonices Mundi and argue that Kepler seeks to provide a geometrical system that directly links the theorist with the world. Finally, I show how he applies this system to his astronomy via his harmonic theory. This account not only helps us to understand Kepler’s scientific methodology better but also sheds light on Kepler’s enthusiasm for the results of the Harmonices Mundi by showing how they provide an example of the successful application of his geometrical epistemology. (shrink)

During the 17th century, important conventions for the visual representation of the Earth as a whole were established by writers of Theories of the Earth. This essay examines how the emergence of visual representations contributed to the establishment of a new print tradition of multicontextual discourse and critical debate. Four vignettes contrast varying uses of global depictions: the incidental global depictions and mathematical vision of Johannes Kepler; the cosmogonic sections and chemical vision of Robert Fludd; the geogonic sections and mechanical (...) vision of René Descartes; and the global views and classical vision of Thomas Burnet. The continuities of visual conventions and the contrasts of disciplinary perspectives and local contexts observed in these vignettes conforms well to the characterization of Theories of the Earth as an interdisciplinary print tradition. (shrink)