The Trial of Galileo, 1633 AD

It's not that simple to say that the condemning of Galileo was strictly a conflict of science and religion, although it was considered a real assault by many people on their Christian faith.

By Galileo’s day in the early 17th century the Catholic Church felt compelled to take a definite stand against the Copernican heliocentric hypothesis (the Protestants had done this much earlier). Why? “If the earth truly moved then no longer could it be the fixed center of God’s Creation and his plan of salvation. Nor could man be the central focus of the cosmos. The absolute uniqueness and significance of Christ’s intervention into human history seemed to require a corresponding uniqueness and significance for the Earth. The meaning of redemption itself, the central event not just of human history, but also of universal history, seemed at stake. To be a Copernican seemed tantamount to atheism.” (Richard Tarnas The Passion of the Western Mind, pp. 253-254).

Previously Dante harmonized religion and science by “poetically uniting the specific elements of the Christian theology with the equal specific elements of classical astronomy. The Aristotelian geocentric universe thus became a massive symbolic structure for the moral drama of Christianity. All of the Ptolemaic planetary spheres took on Christian references, with specific ranks of angels and archangels responsible for each sphere’s motion. Every aspect of the Greek scientific scheme now was imbued with religious significance. If, for example, a moving earth were to be introduced into that system, the effect of a purely scientific innovation would threaten the integrity of the entire Christian cosmology.” (From Richard Tarnas, pages 195-6).

According to Diogenes Allen, the Aristotelian/Ptolemy view “included values as part of the very fabric of the universe...obligations and rights...are confirmed and supported by the physical order of the cosmos itself.” Therefore “it seemed to threaten the very foundations of the social, political, and moral order.” [Christian Belief in a Postmodern World, (John Knox Press, 1989, p. 41, 42)].

The invention by Galileo of the telescope changed the debate. It destroyed several Ptolemaic conceptions: A) They believed that the spheres of the universe were perfect, yet Galileo noticed the moon has craters; B) They believed everything rotates around the earth, yet Galileo discovered Jupiter had four moons; C) They believed the heavenly bodies were eternal, yet Galileo discovered sun spots indicating that the sun was decaying. He defended the Copernican system with observations, and thus began the rise of experimental science! He showed (contrary to Aristotle) how heavier rocks do not fall faster than lighter ones by experimentation. He even conceptualized tying a string from a heavier rock to a lighter one, thus making them one object! But would the combined rock now fall faster than either one, or would the lighter one drag? Such problems plagued the older Aristotelian view.

But look at how Galileo’s views were answered by Florentine astronomer Francesco Sizzi: “There are seven windows in the head: two nostrils, two eyes, two ears, and a mouth. So also in the heavens there are two favorable stars, two unfavorable, two luminaries, and Mercury alone undecided and indifferent. From all this, and from other such natural phenomena, such as seven metals, etc., all too pointless to enumerate, we can conclude that the number of planets is necessarily seven.” “Furthermore, the alleged satellites of Jupiter are invisible to the naked eye, and therefore can have no influence on earth, and therefore would be useless, and therefore do not exist.” “Besides all this, the Jews and other ancient peoples as well as modern Europeans have always divided the week into seven days and have named them after the seven planets. Now if we, like Galileo, increase the number of planets, this whole and beautiful system falls to the ground.”

What must be understood about the trial: 1) There was real debate about the geo-centric system--but it was to be regarded as a “hypothesis not fact.” 2) Copernicus and Galileo’s systems contained ideas that were “hopelessly inaccurate,” and there was no evidence yet for things that should be noticed. For instance a) the proper planetary orbits were not known yet--they were arguing for more complete circles revolving around the sun, also, b) There was “no observable stellar parallax”—individual stars should appear at different points in the sky when the earth is at its two farthest distances in its cycle around the sun. Either the stars were immensely more distant, which we know now is the case, or the earth didn’t move. Thus, the Copernican system was not yet established on scientific grounds! 3) The Pope, Urban VIII, felt personally betrayed by Galileo, a former friend, because he thought one of the incompetent speakers in the Dialogue of Two Chief World Systems was intended to represent him.