Peter’s Denial and Kepler’s Witch Trial

Kepler, the astronomer who saved his mother from being burned as a witch.

Aidan Rocke

Christian role models and the Historicity of Jesus Christ:

In a Brave New World that is devoted to engineering a Technological Tower of Babel, it is not obvious to find legitimate Christian role models that can inspire us. Recently, a friend of mine shared a Christian enigma to which no proponent of individualism or atheism can offer a decent answer:

For what will it profit a man if he gains the whole world, and loses his own soul?-Christ

This may be enough to convince ordinary people of Christ’s exceptional wisdom but for the vast majority, believing that Christ is the Son of God would be a bridge too far. Provide me with a demonstration of a single one of Christ’s miracles, they might say, and we would be willing to believe in Him.

Peter’s Denial:

However, this conditional statement suffers from an essential weakness. Every single one of Christ’s miracles was designed to reveal a fundamental truth about Human Nature and Man’s relationship with God. If not for this, Christ would not be so different from a Persian Magus. What does it mean for an ordinary person to start believing in Christian truths? Does the truth mean anything to those who are not willing to defend it?

What Christ revealed through the Prophecy of Peter’s Denial was the fundamental weakness of this conditional statement; the general cowardice of Man when confronted with the Moment of Truth. Peter, who witnessed all the miracles of Jesus was incapable of deviating from the mimetic phenomenon. Under incredible peer pressure, and the spectre of severe torture, Peter suddenly forgot who Jesus was. Thus, the Prophecy of Peter’s Denial reveals the fundamental difference between Man and God, and defines the ultimate test for a true Christian.

Kepler’s Witch Trial:

This begs the question: if Christ represents the ideal role model that lies at the midpoint between Man and God, then who lies at the perfect distance between Christ and Man? If not Peter or the Pope, then who? Besides Joan of Arc and Emmanuel Swedenborg, one other historical figure that comes to mind is Johannes Kepler. Kepler believed that he had a unique ability to understand God’s design of the Universe. If you consider that he was among the three greatest astronomers before the Modern Age alongside Galileo and Newton, it is hard to counter this claim.

In 1615, at the height of Kepler’s scientific influence, 24 witnesses accused Kepler’s mother of being a witch. Kepler, then the Imperial mathematician to Emperor Rudolf II, took over his mother’s legal defense. Little did he know that the case would go on for six years.

The accusation came after Christoph Kepler, Kepler’s younger brother, accidentally shared a copy of Kepler’s Somnium(1608)…a book which details how a witch raises a young Icelandic boy to become a great astronomer that works with Tycho Brahe. The accusation of Katharina Kepler tore the family apart.

Unlike Johannes, Heinrich Kepler(Kepler’s older brother) was ready to accuse her before the authorities. As the case went to trial, Christoph withdrew his support completely as he feared the open contempt of the people. Only Johannes stood firmly by her side, notwithstanding the collateral damage his reputation might suffer as a result of being considered guilty by association.

Johannes uprooted his family and put aside his scientific work for nearly a year to defend Katharina Kepler during her trial. The astronomer defended his mother as best he could. As befitted a mathematician, Johannes weighed the evidence, applied reason and logic to defend Katharina. After 14 months of incarceration, Katharina was absolved of all charges. However, she was forbidden to return to her village and she died from the stress of incarceration six months later.

European Witch Trial statistics:

In her book, The Astronomer and the Witch(2015), Ulinka Rublack, a professor of History at Cambridge, provides us with historical perspective. 73,000 civilians were tried for witchcraft and 40,000-50,000 were executed in Europe between 1500 and 1700. More than half of all victims, around 22,000, were executed in Germanic territories between 1560-1700.

In comparison, the Spanish, Portuguese and Roman Inquisitions are estimated to have carried out 300,000 trials against all kinds of heresy and executed around 13,860 civilians. This means that you were five times more likely to be destined for execution as a German witch at the commencement of a witch trial compared to a victim of the Spanish Inquisition.


For attribution, please cite this work as

Rocke (2023, July 5). Kepler Lounge: Peter's Denial and Kepler's Witch Trial. Retrieved from

BibTeX citation

  author = {Rocke, Aidan},
  title = {Kepler Lounge: Peter's Denial and Kepler's Witch Trial},
  url = {},
  year = {2023}