We are in the last years of the sixteenth century, at the beginning of a new and bitter season for European culture. A small minority of philosophers and mathematicians are engaged in the search for the foundations of a new constitution of the universe. This book reconstructs its genesis and early developments through an in-depth examination of the human and intellectual fortunes of two of the major protagonists of modernity: Galileo and Kepler.

The two scientists are not simply presented in their roles as "pioneers" and "winners". This book also shows them developing a new physics and a new astronomy. We see them grappling with celestial observations but also with thorny religious and political issues that were inseparable from their projects and intellectual strategies. In the separate and hostile worlds in which they had to live, Kepler and Galileo suffered the insults of the men of their time: Kepler was excommunicated by the Lutheran Church for his Calvinist ideas on the Eucharist, Galileo was sentenced to life imprisonment by the Church of Rome for his scandalous defense of heliocentrism.