Faith and Science: Kepler’s Witch, Book Review

“Here’s harmony! . . . here’s repose!” –Fanny Price in Mansfield Park, looking at the night sky.

In Austen’s England, most people saw no conflict between science and religion. Breakthroughs in astronomy by William and Caroline Herschel began to raise some new questions. But their discoveries were rooted in much earlier ones.  Two hundred years before, two astronomers of deep faith, Galileo and Kepler, had struggled for acceptance of their view of God’s world.

Galileo’s Daughter: A Historical Memoir of Science, Faith, and Love, by Dava Sobel, and Kepler’s Witch: An Astronomer’s Discovery of Cosmic Order Amid Religious War, Political Intrigue, and the Heresy Trial of His Mother, by James A. Connor, explore the inspiring struggles of men who loved both God and the stars. They lived during the late 1500s and early 1600s, when Europe was torn apart by wars of religion—Catholic against Protestant, Protestants against one another.  Each book focuses on the man’s faith, his family, his discoveries, and opposition he faced.  Galileo was a committed Catholic; Kepler a committed Lutheran (Protestant).  Each book includes original letters translated for the book: letters written by Galileo’s daughter, a nun, and letters written by Kepler and his contemporaries.

This week we’ll focus on Kepler’s Witch, and next week we’ll look at Galileo’s Daughter.

Kepler’s “Witch”

Johannes Kepler’s “witch” was his mother.  A poor, uneducated woman, she, like many others, prepared herbal remedies for people in her village.  When she aroused the jealousy and anger of more influential villagers, they accused her of witchcraft.  She suffered long periods of imprisonment where she had to pay for her own and her guards’ upkeep, several trials, and an odd form of torture. She was shown all the instruments of torture, torture was described to her, and she was adjured to confess and repent, though they did not harm her body. She stayed firm in her denial of any wrongdoing and was eventually released. Her famous son’s attempts to clear her helped maintain her through her trials. But she died sad and broken.

Kepler's Witch

Kepler’s Science

Kepler (1571-1630), a mathematician as well as astronomer, investigated the orbits of the planets.  His mentor was a Danish astronomer, Tycho Brahe, who had spent years making observations of the planets.  It was believed that the planets must have circular orbits, as the circle was the perfect shape, but more and more complex manipulations were needed to match the available data.

Kepler discovered that Mars, and the other planets, moved in an elliptical orbit—simple and elegant, but not circular.  As Copernicus had earlier theorized, the planets circled the sun, not the earth. Kepler’s three laws of planetary motion mathematically describe the paths of the planets around the sun. These laws, along with Kepler’s other discoveries and hypotheses, were a major step toward Isaac Newton’s law of gravity, developed about seventy years later. Kepler also discovered laws of optics explaining how light passes through lenses; obviously important in the development of better telescopes.

Kepler’s Faith

Connor says, “To understand Kepler the man, the philosopher, the scientist, . . . one must first understand Kepler the Lutheran. The new faith was in his marrow, and all his science was at heart a prayer” (chapter 3). Like Anglicans in England, Lutherans in Germany saw themselves as a middle way between the extremes of Catholicism and of “radicals” such as Anabaptists and Calvinists.

Kepler and others of his time (and Austen’s) believed that the created world reflected God’s mind, and that the heavens were the most perfect reflection of God’s order and harmony. Kepler’s life work was to discover the harmony of the universe, far above all the disharmony on earth. He strove to understand God’s mind.

Kepler’s masterwork, Harmony of the World, was written in the midst of great discord on earth, during wars of religion.  He sought to combine philosophy, astronomy, music, geometry, and theology, believing they all reflected God’s perfect mind. His third law of planetary motion was introduced in this book.

In Kepler’s day, astronomy was still closely intertwined with astrology (as chemistry was for a long time intertwined with alchemy).  Kepler wrote astrological predictions to please his patrons, though they were based more on his observations of human events than on the stars.  He believed that “the stars helped to shape the general flow of the world, its tendencies and its limitations, but did not control individual events” (chapter 3).

Kepler’s Struggles

Kepler was caught in the midst of wars of religion. The people of any territory had to accept the religion of their ruler. (Henry VIII followed the same policy, making England Anglican rather than Catholic; freedom of worship for other denominations only came slowly, and was still an issue in Austen’s England.)  While Kepler did face some opposition from those who did not accept that the earth moved around the sun, the more major conflicts he faced were religious. Kepler had to move his family often because of the shifting politics and religions of the areas where he worked and the schools and leaders he worked for.

Lutheranism “was a religion that made sense to him. He saw it as a religion that never asked him to submit his reason to any other authority than God” (chapter 4).  By the same token, Kepler studied the Bible for himself and did not always agree with his own church.  At one point he was excommunicated because he differed somewhat from Lutheran doctrine about the nature of the Lord’s Supper.

However, he would never convert to Catholicism for Catholic rulers, even though conversion would have been to his advantage financially.  He was friends with Jesuits and other Catholics who discussed many topics with him; they attempted to convert him but could not.  The Lutheran Kepler and the Catholic Jesuits had much in common: “the Jesuit motto to ‘find God in all things’ was similar enough to Kepler’s own view of mathematics and astronomy that Kepler and the Fathers of the Society of Jesus found that they were kindred souls, that they were all men of scholarship and faith” (chapter 15).

Conflicts about science were discussed within the church(es). “Twenty-first-century people often imagine that the Copernican controversy was about science against the church, but the reality was far more complex. Science as we know it did not yet exist, and the church, Protestant and Catholic alike, was in fact the normal place for intellectual discussion” (chapter 4).

Despite great difficulties in finding places to live and work and a steady income to support his family, Kepler kept his Lutheran faith while keeping good relationships with those of other beliefs. Unlike most people of his day, Kepler “believed that all Christians—Calvinists, Lutherans, and even Catholics—should respect one another as Christians” (chapter 9). When Kepler was dying, he said his hope was all in Christ.  He is remembered as “the great man who proved Copernicus and helped set the course of science.”

Kepler’s Witch gives fascinating insights into the scientific and religious issues and struggles of the early seventeenth century, which set the stage for issues faced later in Austen’s England.  Unfortunately the book is sometimes repetitious and jumps around in time, which can be a bit confusing.  The paperback version would probably be easier to follow than the kindle version that I read. However, its perspective and view of the times make the book well worthwhile for anyone interested in the intersections of faith and science.

Science provided a common ground of discussion for different denominations in Kepler’s Europe. What common grounds of discussion can we find today, to connect us with those we differ with in some areas of faith? A few examples I’ve seen: Catholics and various groups of Protestants sometimes unite over the issue of abortion. A Muslim friend living in a formerly Communist, now mostly atheist, country found she had much in common with a Christian neighbour, because both believed in God and sought to follow him. Creationists, interested in harmonizing scientific discoveries with a literal interpretation of Genesis,  may include people of various faiths.  Finding common ground (which for you may be very different than these examples, of course!) helps us respect and appreciate one another, as well as listen to one another in the areas where we differ. 


Connor, James. A. Kepler’s Witch: An Astronomer’s Discovery of Cosmic Order Amid Religious War, Political Intrigue, and the Heresy Trial of His Mother. Harper Collins ebooks, 2004, 2008. Kindle.

Illustrations from Kepler’s Harmony of the World Book 5, 1619.


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