Dark Side
17th Cent. (1601-1700 A.D.)

Last Update: Sept 3, 2007




The Galileo / Church Conflict (1604-1642)

The great obstacle to learning in the late 16th century was the dominance of Aristotle's writings, especially his account of the universe, whose central feature, famously, was that the Sun revolved around the Earth, which stood still. Aristotle's own contemporaries - Democritus among them - took the opposite view, but Aristotle decisively won the battle of ideas when he was adopted by the early Christian church: the fixity of his conceptions made them eminently controllable; crucially, too, they chimed exactly with the account found in the Bible.

Aquinas's 13th -century endorsement of Aristotle's writings gave them the force of revealed truth, which meant that scientists were up against two incontestable authorities, classical and scriptural.

Galileo proceeded as if both were irrelevant, and though shrewd enough not to be combative about the difference between what Aristotle and the Bible said and what he himself observed, he discussed his ideas freely among his intellectual equals in the wonderfully named Academy of Lynxes - the sharp-eyed ones - writing his thoughts down in pamphlets and books in witty, accessible Italian (rather than Latin, the official language of intellectual discourse).

He took it as read that the Bible was not the literal truth and that Copernicus's theories about the rotation of the Earth around the Sun were sound. For this he was increasingly denounced, at first unofficially - "geometry is of the devil", a rogue Dominican priest ringingly declared from his pulpit, "and mathematicians should be banished as the authors of all heresies" - but then more widely. Vexed, he decided to get papal approval for his writings.

The shrewd, reactionary Cardinal Bellarmine demanded of him that he undertake to teach and discuss Copernicus's theory merely as a hypothesis; Galileo sensibly accepted this limitation, went home and immediately started writing even more provocatively. He simply couldn't believe that the authorities really meant what they said: that if he spoke the truth honestly and decently he would be severely punished.

His vivacious third book provoked a storm when the new pope became convinced that he was the butt of its sparkling satire. As Urban VIII, the formerly sympathetic Cardinal Barberini had taken to disinterring heretics to display their rotting remains to the populace. These were dangerous times, and intellectual dissent was a luxury which would no longer be indulged.

When it was discovered by the Holy Office that Galileo had, in an earlier work, The Assayer, espoused the atomic theory of matter, he was held by implication to have criticised the Eucharist. To question the mystical doctrine of transubstantiation was an even greater transgression than to assert the universe's heliocentricity, and Galileo was summoned to Rome to answer the charges against him.

In White's brilliant account of Galileo's trial, recently discovered documents that make clear the centrality of the issue of transubstantiation (of the Eucharist).

By comparison with many other alleged heretics - Giordano Bruno, for example, who was burned at the stake - Galileo, who was merely threatened with torture, had a relatively kid-gloved experience. It nearly broke him, nonetheless. But not quite. After returning home, despite being under house arrest, he was allowed to receive visitors (among them Milton and Hobbes); he continued, blind though he was, to speculate, writing his final revolutionary work, The Discourses, in his eighth decade, still able, in his son's words, to crack a joke.

- from Simon Callow, The Guardian Aug. 4 2007


The Appearance of Kepler's Nova in the sky; Galileo debates its significance with conservative scholars.


The Telescope: News of the invention of the telescope reaches Italy; Galileo develops his own device in August. Autumn 1609: Galileo makes his first observations using his telescope, discovers the uneven surface of the moon.


Moons of Jupiter Discovered

Jan: Galileo discovers four moons orbiting Jupiter.
Mar: Publication of Sidereus Nuncius, dedicated to the Grand Duke of Tuscany, Cosimo II.
Jun: Galileo leaves Padua to take a new, more lucrative position in Tuscany


Galileo goes to Rome: He is cordially received by the Jesuit astronomers and Pope Paul V


Galileo Attacked: Father Tommasso Caccini attacks Galileo in a sermon in Florence, and later denounces him to the Inquisition.


Galileo's 2nd Rome Visit: Galileo returns to Rome.
March: Papal commission issues edict against Copernican theory; Cardinal Bellarmine orders Galileo to cease in his support of heliocentricity.
June : Galileo again leaves Rome.


Death of Cardinal Bellarmine


Galileo's 3rd trip to Rome
June : Urban VIII becomes Pope; Galileo visits him in Rome.
Oct: Galileo's treatise on comets, The Assayer, is published with Urban VIII's blessing.


Galileo writes the Dialogue

Galileo works on his Dialogue Concerning the Two Chief World Systems from his home outside Florence.


Feb: The Dialogue Concerning the Two Chief World Systems published in Florence, with tentative Papal approval, but:
Aug: The Papal Inquisition bans further printing of the Dialogue.
Sept: Galileo is summoned to Rome again.


Trial of Galileo

Feb 13: Galileo arrives in Rome
Apr 12: Galileo interrogated for the first time. Afterwards, he is imprisoned in the Vatican for three weeks.
Apr 30: Galileo interrogated again, and allowed to return to the home of the Tuscan ambassador.
May 10: Third interrogation; Galileo begs for mercy.
Jun 21: · Final interrogation. The following day, Galileo is officially charged with heresy; he is forced to confess his errors, renounce the Copernican system, and accept the Church's judgment. He is sentenced to imprisonment "for a period determinable at our pleasure."
Dec: Galileo is allowed to return to the village of Arcetri, outside Florence, where he lives under house arrest.


Galileo's eyesight begins to fail.


Galileo's Dialogues Concerning Two New Sciences is published in Holland. John Milton visits Galileo in Arcetri.


January 8, 1642: Death of Galileo