Next, it is clear that Galileo's condemnation was unjust and the Decree of 1616 was incorrect in declaring the doctrine of the earth's motion ``false'' and ``contrary to the Holy Scripture.'' But the Church doctrine of infallibility was not thereby violated. The decree was not an ex cathedra statement or even a pronouncement of the Holy Office, but only an edict of the Sacred Congregation of the Index. As such it was binding on the consciences of Catholics, but capable of being revoked, as it eventually was. Although there are indications that both Pope Paul V and his successor Urban VIII favored stronger action in the case, cooler heads prevailed and the highest authority of the Church was not committed to an erroneous position.
Also, we can say that to a large extent Galileo provoked the action against him through his meddling in theology and the interpretation of Scripture. However, as I have argued, it would have been difficult for a man of his temperament to act in any other way. He persistently held to the belief that anyone who impartially examined the evidence would be persuaded, as he had been, of the reality of the heliocentric system. But he was unable to get a hearing: they did not want to listen, convinced that science could not conclusively prove anything about the constitution of the heavens. As Pope John Paul II has put it, ``The error of the theologians of the time was to think that our understanding of the physical world's structure was in some way imposed by the literal sense of Scripture.''
Finally, although Galileo did not succeed in averting a scandal in the Church over the condemnation of the Copernican theory, this episode ultimately did have the effect he sought of reforming the Church's attitude toward the relationship between faith and science. Within a few decades after Galileo's death in 1642, further astronomical discoveries, and especially Isaac Newton's theory of universal gravitation (which gave a simple explanation of Kepler's three laws of planetary motion), led to universal acceptance of the heliocentric model. The decree of 1616 quietly became a dead letter. (The wheels of the Curia turn slowly, and the decree was not officially revoked until 1822.) When in later centuries, debates arose over the age of the Earth, the evolution of species, and the origin of the universe, the Church remained aloof, leaving scientific questions to be resolved by the scientists.
In 1893 Pope Leo XIII wrote in an encyclical:
There can never, indeed, be any real discrepancy between the theologian and the physicist, as long as each confines himself within his own lines, and both are careful, as St. Augustine warns us, ``not to make rash assertions, or to assert what is not known as known.'' ... [T]he sacred writers, or to speak more accurately, the Holy Spirit ``who spoke by them, did not intend to teach men these things (that is to say, the essential nature of the things of the visible universe), things in no way profitable unto salvation.''These words echo Galileo's arguments in his Letter to the Grand Duchess Christina. Galileo can be given substantial credit for bringing about this reconciliation of faith and science.