The Mongols besieging Baghdad, c. 1430, Bibliothèque nationale de France

The Mongols conquer Baghdad on January 29, 1258. The fall of Baghdad marks the fall of the ʿAbbāsid Caliphate and the Islamic Golden Age. Symbolically, the Tigris is said to run red with blood and black with ink.

Pope Leo III crowning Charlemagne, 14th century illumination.

Charlemagne is another ambiguous character. After he becomes Holy Roman Emperor in 800, he revives the Latin language and rescues ancient manuscripts from oblivion. But he also makes blasphemy a capital crime and converts heathens by the sword.

“Ah, woe is me! that I was not thought worthy to see my Christian hands dabbling in the blood of those dog-headed fiends.”
– Charlemagne on the Scandinavian Vikings recorded by Notker the Stammerer in De Carolo Magno, 9th century.

Europe’s first universities are born in Paris and Bologna around the year 1200 when masters and students form guilds known as universitas magistrorum et scholarium. A few years later, the first English universities evolve in Oxford and Cambridge. By 1300, Europe has 18 universities. By 1500, it has 70.

With the rise of the university, masters of theology assume the role of heresy police from the church. There are about 50 known cases of academically related heresy trials in the thirteenth and fourteenth centuries.

The first victim is Master Amalric of Bène. Around 1206, he is found guilty of false teaching because of his pantheism. Four years later, he is excommunicated and his followers are burned at the stake outside the gates of Paris.

But the majority of cases convict books and not persons. Most offenders are free to continue their careers if they recant their views and burn the problematic books.

Thomas Aquinas sitting between Plato (right) and Aristotle (left). Benozzo Gozzoli: Triumph of St. Thomas Aquinas, 1470-1475

Thomas Aquinas becomes one of the most influential thinkers in Medieval Europe when he reconciles Christian theology with ancient Greek philosophy. For instance, he uses principles from Aristotle to prove the existence of God.

In 1277, many of Aquinas’ propositions are condemned and banned by the Bishop of Paris.

Reason in man is rather like God in the world.
– Thomas Aquinas, Opuscule II, De Regno

Glass mosaic in Surrey

The friar and philosopher William of Ockham is best known for his razor: The problem-solving principle of choosing the explanation based on fewest assumptions. In 1339 and 1340, two statutes ban Ockham’s ideas from the faculty of arts at the University of Paris.

‘Purely philosophical assertions which do not pertain to theology should not be solemnly condemned or forbidden by anyone, because in connection with such anyone at all ought to be free to say freely what pleases him.’
– William of Ockham, Dialogus vol. 1, bk. 2, ch. 22

From the High Middle Ages, Europe developed into a “persecuting society,” obsessed with stamping out the “cancer” of heresy. But questions about how this was accomplished — and the consequences of these developments — abound:

• Why did popes and secular rulers shift from persuasion to persecution of heretics?
• Why was human choice in matters of religious belief considered a mortal threat to Christendom itself?
• Why did bookish inquisitors armed with legal procedure, interrogation manuals, data and archives succeed where bloody crusades and mass slaughter failed?
• How did the “machinery of persecution” developed in the Late Middle Ages affect other minority groups such as Jews?
• Are inquisitions a thing of a past and dark hyper-religious age, or a timeless instrument with appeal to the “righteous mind” whether secular or religious?
• What are the similarities between medieval laws against heresy and modern laws against hate speech?

We try to answer these questions — and more — in episode 8 of Clear and Present Danger: The Hounds of God.

Jan Hus at the stake. Spiezer Chronik, 1485

The Bohemian theologian Jan Hus is burned to death in Jena on July 6, 1415. The execution is a sign of times to come: The number of religious executions grow rapidly in Europe in the 15th and 16th centuries.

But I rejoice that they were compelled to read my books, in which their wickedness was revealed. I know that they have perused these books more carefully than the Holy Scriptures in their desire to discover my errors.
– Jan Hus in a letter, nine days before his execution

Spanish Jews pleading with Isabel, Fernando and grand inquisitor Tomás de Torquemada in a painting by Solomon A. Hart.

The Alhambra Decree issued by Fernando and Isabel expels all practising Jews from the Kingdoms of Castile and Aragon and their possessions. Also known as the Edict of Expulsion, it is issued on 31 March 1492 and effective from 31 July.

Woodcut of early printing workshop (Public Domain)

Around 1448, the German goldsmith Johannes Gutenberg (c. 1400 – 1468) gets a brilliant idea: He takes a printing press and breaks reconstructs its printing surface into changable components. He sets up a print office in Mainz and prints his first Bible around 1454.

Gutenberg’s invention quickly goes viral. Before long, printing presses appear in Germany, Italy, France and the Low Countries. Then they crop up in Bohemia, Poland, England, Spain, Portugal, and Scandaniva. The number of operating printing presses in Europe rises from around 15 in 1471 to at least 87 in 1480.

The Gutenberg Revolution has a profound influence on cultural and intellectual movements like the Renaissance, the Reformation and the Scientific Revolution.

“In a free state, tongues too should be free.”
– The Education of a Christian Prince (1516)