The Dream of Kepler: A Retrospective Work on the Human Side of the Scientist

The compendium Epitome astronomiæ copernicanæ, published between 1618 and 1621, is considered the most complete and influential work of Johannes Kepler (1571-1630), introducing the reader to the heliocentric theory and the whole astronomical work of its author. However, there is another lesser known masterpiece that deserves comparable attention: the Somnium, seu opus posthumum de astronomia lunari (published posthumously, in 1634), depicting Kepler not only as a scientist but also as a man. It is the short tale of a dream, whose troubled drafting lasted for almost forty years, describing the journey to the Moon made by a fictional young man, whose life shows several affinities with Kepler’s one. In its pages and in its rich apparatus of explanatory notes, added by Kepler himself, several references to the major works and to the life of the astronomer can immediately be found. The Somnium is thus a journey through Kepler’s theories, that provides the reader with an accurate portrait of an exceptionally modern character (defender of both the Copernican model and the central role of science) but still tied to the past (in his Platonic and Pythagorean ideas). Thanks to the Somnium it is possible to draw the fundamental steps in Kepler’s life and in his work, surely deserving a special place in the history of astronomy.