This book traces the development of Kepler's ideas along with his unsteady wanderings in a world dominated by religious turmoil. Johannes Kepler, like Galileo, was a supporter of the Copernican heliocentric world model. From an early stage, his principal objective was to discover "the world behind the world", i.e. to identify the underlying order and the secrets that make the world function as it does: the hidden world harmony. Kepler was driven both by his religious belief and Greek mysticism, which he found in ancient mathematics.

His urge to find a construct encompassing the harmony of every possible aspect of the world – including astronomy, geometry and music – is seen as a manifestation of a deep human desire to bring order to the apparent chaos surrounding our existence. This desire continues to this day as we search for a theory that will finally unify and harmonise the forces of nature.