Johannes Kepler was born in the midst of an exciting and confusing time for Europe. The continent was entering the Renaissance, a reawakening of thought across the continent. By the time of Kepler's birth, the Renaissance had reinvigorated European culture, politics, philosophy, religion, literature, and science. The authority of the Catholic Church was challenged for the first time in centuries by the reformer Martin Luther, who pointed out the wrongs that he felt the Church had committed. Luther's rebellion spurred the Protestant Reformation, in which Luther and his followers freed themselves from the authority of the Church, creating a new sect of Christianity. Kepler, a Protestant, often found himself caught in the midst of the resulting tension between Catholicism and Protestantism. Catholics frequently persecuted him.
A similar challenge of scientific authority was also in progress, a radical shift in thought that later became known as the Scientific Revolution. Scientists in all fields were beginning to question the wisdom of the ancient philosophers who had molded their disciplines. They gradually began rely on objective facts and observation and to turn away from the mysticism, religion, and unfounded theorizing that had previously dominated the field. This drastic change in scientific practices and beliefs was most apparent in the field of astronomy.
Physics and astronomy had been dominated by the work of Aristotle, a philosopher from the time of ancient Greece, and Ptolemy, an astronomer from the second century A.D. Astronomy was rooted in both philosophy and theology, and it was difficult for scientists to separate their work from that of the mystics or the clergy.
Through the work of the four fathers of the astronomical revolution, Copernicus, Kepler, Galileo, and Newton, both the practice of astronomy and man's view of the universe were transformed. Astronomers rejected the Ptolemaic view of the universe that had held court for centuries. They supplanted Ptolemy's earth-centered universe with a new sun-centered system. These modern thinkers, far ahead of their time, persevered against the mockery, apathy, and anger of their peers. And eventually, through Newton's synthesis of math, physics, and astronomy, they triumphed.
The work of these astronomers shook the world. They denied everything that humans had held certain for centuries. The excitement and confusion that these astronomers left in their wake in is reflected in John Donne's seventeenth century poem "An Anatomy of the World – The First Anniversarie." As he wrote, "And new Philosophy calls all in doubt. 'Tis all in pieces, all coherence gone. "