The Galileo incident

In the 17th century, science and religion collided.

Known to students of history as simply Galileo, Galileo Galilei (1564-1642) lived toward the end of the European Renaissance period. Widely renowned, he was a brilliant astronomer, mathematician and physicist of his time, and he often is called the Father of Observational Astronomy and Father of Modern Physics.

From all indications he was a devout Catholic, even encouraging his daughters to become nuns, and thus it seems odd that this apparently Christian man would come into any sort of conflict with the Church, let alone be accused of heresy.

Geocentric theory

For 1,500 years, people believed that the sun revolved about the earth (geocentric theory). Such was the teaching of the Greek astronomer Ptolemy (c. 100-170 A.D.), which confirmed the Church dogma anchored in several sacred Scriptures. One such example comes from the book of Joshua:

“It was then when the Lord delivered up the Amorties to the Israelites, that Joshua prayed to the Lord, and said in the presence of Israel: Sun stand still at Gibeon, Moon, in the valley of Aijalon! The sun stood still, the moon stayed, while the nation took vengeance on its foes. This is the record in the Book of Jahar. The sun halted halfway across the heavens; not for an entire day did it press on. Never before or since was there a day like this, when the Lord obeyed the voice of a man” (Jos 10: 12-14).

The Church taught, and people believed, that the sun moved, not the earth.

Prior to Galileo, Nicholas Copernicus (1473-1543) developed a theory advocating that mankind, including Ptolemy as well as Aristotle (384-322 B.C.), were wrong in their thinking about the rotation of the planets. He concluded that the earth moved and the sun was the center of the universe (heliocentric). The earth, he believed was spinning while rotating around the sun. The Catholic Church rejected this theory as being in opposition to the Scriptures and would eventually ban Copernicus’ book: “On the Revolutions of the Heavenly Spheres.”

Galileo’s findings

Galileo concluded some years later that Copernicus was right. In 1609 he developed a telescope powerful enough to more closely study the movements of the planets and thus supported both Copernicus and his own developing theories. He, like Copernicus, was belittled by some of his colleagues, and Galileo was cautious at first about trying to publish his work in lieu of how the Church had dealt with the issue, and with Copernicus himself.

An Italian priest named Tommasso Caccini argued against and even mocked Galileo in a homily referring to the Book of Acts, where Jesus’ followers watch him being taken up to heaven: “... Men of Galilee [Galilei], why are you standing there looking up to the sky?” (Acts 1:11).

Many people dismissed Galileo. If the earth was moving wouldn’t we know it? Wouldn’t we feel it?

In an effort to solicit support for his work, Galileo wrote a letter called “Concerning the Use of Biblical Quotations in Matters of Science” to Madame Christina of Lorraine, the Grand Duchess of Tuscany. Written in 1615, this long, well-articulated letter was an attempt by Galileo to explain his findings, reconcile science with Scripture and express his offense with the way his work had been rejected especially within the Church.

Galileo wrote: “I shall therefore discourse of the particulars which these men produce to make this [his] opinion detested and to have it condemned not merely as false but heretical. To this end they make a shield of their hypocritical zeal for religion. They go about invoking the Bible, which they would have minister to their deceitful purposes. Contrary to the sense of the Bible and the intention of the holy Fathers, if I am not mistaken, they would extend such authorities until even in purely physical matters-where faith is involved-they would have us altogether abandon reason and the evidence of our senses in favor of some biblical passage, though under the surface meaning of its words this passage may contain different sense.”

Galileo clearly enunciates his thinking that the Bible should not be used to deny scientific fact, citing St. Augustine several times and quoting Cardinal Cesare Baronius (1538-1607) that the Holy Spirit uses the Bible to teach “how one goes to heaven not how the heaven goes.”

This letter to the Duchess of Tuscany did not endear Galileo with the Vatican because he crossed over from scientist to theologian.

That same year, 1615, Galileo went to Rome to argue his theories at the Vatican. He had a temper, was stubborn, and his anger showed through in many of his discussions with Vatican officials. In the end St. Robert Bellarmine (1542-1621), then a cardinal, warned that, without proof, the Church would not accept Galileo’s findings: “I say that, if there were a true demonstration that the sun was in the center of the universe ... then it would be necessary to use careful consideration in explaining the Scriptures that seemed contrary. ... But I do not think there has been such demonstration” (“The Galileo Connection,” InterVarsity Press).

Urban VIII and Galileo

When Maffeo Barberini, a friend of Galileo, was installed as Pope Urban VIII in 1623, it seemed that there would be new hope for the theories of Galileo. The pope and the scientist had several meetings in which the pope encouraged Galileo to continue his work and writings, but in doing so not to claim the theory that the earth orbits the sun as fact.

In 1632, Galileo published a book called the “Dialogue Concerning The Two Chief World Systems, Ptolemaic and Copernican.” While he had obtained Vatican approval for the book, the contents concluded that our universe was sun-centered instead of earth-centered. The Vatican quickly claimed the book not only promoted the erroneous heliocentric theory but also that it disparaged Catholic beliefs. After an investigation, the pope ordered Galileo before the Inquisition tribunal. The charges involved Scripture and astronomy, but also disobedience to the pope, who felt duped by his friend Galileo.


During the Inquisition trial in the spring of 1633, Galileo was forced to recant his writings and theories. The trial judges found him guilty of heresy, “that he [Galileo] believed and held doctrine which is false and contrary to sacred Scripture ... that the sun is the center of the orbit of the world, and that it moves not from east to west, and the earth moves and is not the center of the world.” They would absolve him, “provided first, that with a sincere heart and faith, not feigned before, you abjure, curse and detest the above-mentioned error and heresies, and every other heresy and error contrary to the Catholic and Apostolic Roman Church ...” (“Galileo and The Inquisition,” Burns and Lambert). The judges went on to admonish Galileo not to repeat these errors and initially sentenced him to recite the Seven Penitential Psalms once a week for three years and reserved for themselves authority to moderate or change the sentence. His works were banned, his “Dialogue” was placed on the Index of Prohibited books.

Galileo agreed with the sentence. Later he would be placed under house arrest for the remainder of his life. Despite myths, Galileo was neither tortured nor confined to a jail cell.

Pope St. John Paul II on Galileo
On Oct. 31, 1992, Pope John Paul II addressed the plenary session of the Pontifical Academy of Sciences, acknowledging the past tensions between Galileo and the Church:

As rationalized by many historians, Galileo would likely have been better off had he not argued theology and stuck to matters of science. Also, his theories came at a time of crisis in the Church. Protestantism was becoming more and more widespread, and any arguments against Church doctrines or teachings were all suspect and defended against. The magisterium of the Catholic Church jealously and judiciously protects the right to interpret sacred Scripture; the Church is always Christ-centered.

The List of Prohibited Books Index of 1835 did not include Galileo’s “Dialogue” or Copernicus’ “On the Revolutions of the Heavenly Spheres,” and in 1992, Pope St. John Paul II publicly expressed regret over how the Galileo affair was handled, stressing that the Church does not see science and faith as incompatible.

D. D. Emmons writes from Pennsylvania.