Galileo Galilei (15 February 1564 – 8 January 1642)
Thanks to his intuition as a brilliant physicist and by relying on different arguments, Galileo, who practically invented the experimental method, understood why only the sun could function as the centre of the world, as it was then known, that is to say, as a planetary system. The error of the theologians of the time, when they maintained the centrality of the Earth, was to think that our understanding of the physical world’s structure was, in some way, imposed by the literal sense of Sacred Scripture…” – Pope John Paul II, L’Osservatore Romano N. 44 (1264) – 4th November, 1992
Italian physicist, astronomer, mathematician and philosopher Galileo Galilei was one of the foundational figures of modern science. His achievements include the first systematic studies of uniformly accelerated motion, improvements to the telescope and consequent astronomical observations. But his status as a “saint” of the modern world hinges on his persecution by the Catholic Church for courageously championing the Copernican theory that the earth revolved around the sun, in contradiction to scripture, church tradition and the ancient authority of Aristotle and Ptolemy.
The controversy over Galileo’s position stretched more than a decade, but culminated in his trial and conviction as a heretic in 1633. Throughout the ordeal, Galileo maintained his devout faith and firm commitment to the authority of the church, and formally renounced his heretical views immediately upon the court’s decision. Convinced of his sincere repentance, the Holy Court commuted his sentence of imprisonment to house arrest in Florence where he was allowed to continue his scientific work until his death in 1642. Galileo’s offending work (Dialogue Concerning the Two Chief World Systems (1632)) was banned by the Church.
Although the Galileo affair is often cited as evidence that science and Catholic doctrine are inevitably antagonistic, most of Galileo’s scientific findings were in fact embraced by the church as early as 1741, when Pope Benedict XIV granted an imprimatur to publication of a Complete Works of Galileo, but certainly by 1822 when his work was removed from the Index of banned books. In fact, it seems clear that the Galileo affair was part of a sea change in the Church’s understanding of the relationship between science and religion. The famous statement by Cardinal Baronius in defense of Galileo — “the bible teaches the way to go to heaven, not the way the heavens go” — came quickly to be the Catholic Church’s essential position in the wake of the scientific revolution. But Galileo was not fully vindicated until 1992 when, upon the recommendation of a papal commission that reviewed his trial and condemnation, Pope John Paul II formally absolved Galileo and acknowledged the error of the church’s judgment (quoted above).
For Catholics, the Galileo case is worth remembering as a sign that the church is fallible, and that it can and should recognize and repent of its historic failings. Robert Ellsberg puts it very nicely:
There remains a tendency to claim that the church, as it was once said of the earth, cannot move. To this the legendary words ascribed to Galileo remain appropriate. In making his abjuration, he is said to have whispered under his breath, “Nevertheless, it moves.” — Robert Ellsberg, All Saints (1999).