The Epitome astronomiae Copernicanae:
Kepler's Mature Physical Astronomy
It has been ten years since I published my
Commentaries on the Movements of the
Planet Mars [Astronomia nova]. As only a few
copies of the book were printed, and as it had
so to speak hidden the teaching about celestial
causes in thickets of calculations and the rest of
the astronomical apparatus, and since the more
delicate readers were frightened away by the
price of the book too; it seemed to my friends
that I should be doing right and fulfilling my
responsibilities, if I should write an epitome,
wherein a summary of both the physical and
astronomical teaching concerning the heavens
would be set forth in plain and simple speech.
(Epitome, 845; KGW VII, 251)1
THE EPITOME ASTRONOMIAE COPERNICANAE, contains much of the material from Kepler's earlier works, yet stands out in two very important respects. First, it was written for a more general audience, and indeed it gained a relatively wide readership.2 Second, Kepler's mature physics, metaphysics, and astronomy were presented together for the first time. As a result, it is an invaluable resource for exploring the evolution of Kepler's thought, fleshing out his conception of the relationship between physics, metaphysics, and astronomy, and—since the Epitome was intended as a textbook— uncovering what Kepler believed he needed to do to promote his new astronomy.
The Epitome comprises seven books.3 Books I, IV, and V are of particular interest here, for it is in these that methodological issues are addressed directly and the archetypes appear most frequently.4 In book I, Kepler introduced the discipline of astronomy and the nature of its subject matter. He also defended the thesis that the Earth rotates. Book IV concerns the archetypal and physical structure of the universe, and book V the mathematical representation of that universe.