A committed Lutheran excommunicated from his own church, a friend to Catholics and Calvinists alike, a layman who called himself a “priest of God,” a Copernican in a world where Ptolemy still reigned, a man who argued at the same time for the superiority of one truth and the need for many truths to coexist—German astronomer Johannes Kepler was, to say the least, a complicated figure. With The Pursuit of Harmony, Aviva Rothman offers a new view of him and his achievements, one that presents them as a story of Kepler’s attempts to bring different, even opposing ideas and circumstances into harmony.
 
Harmony, Rothman shows, was both the intellectual bedrock for and the primary goal of Kepler’s disparate endeavors. But it was also an elusive goal amid the deteriorating conditions of his world, as the political order crumbled and religious war raged. In the face of that devastation, Kepler’s hopes for his theories changed: whereas he had originally looked for a unifying approach to truth, he began instead to emphasize harmony as the peaceful coexistence of different views, one that could be fueled by the fundamentally nonpartisan discipline of mathematics. 
 

Kepler's successful solution to the problem of vision early in the seventeenth century was a theoretical triumph as significant as many of the more celebrated developments of the scientific revolution. Yet the full import of Kepler's arguments can be grasped only when they are viewed against the background of ancient, medieval, and Renaissance visual theory. David C. Lindberg provides this background, and in doing so he fills the gap in historical scholarship and constructs a model for tracing the development of scientific ideas.

David C. Lindberg is professor and chairman of the department of the history of science at the University of Wisconsin, Madison.