Galileo: Watcher of the Skies by David Wootton
Sunday Telegraph, 10 October 2010
It is a little known fact that in 1532 Copernicus’s sun-centred solar system was presented to an audience in the Vatican. Given the storm that was to come, it is barely believable that the then pope, Leo X, afterwards sent a note of encouragement to Copernicus as the Polish priest laboured to finish his book. On the Revolutions of the Heavenly Spheres was published in 1543 and Copernicus, so the story goes, held the first copy to come off the press just hours before he died. As long as his heliocentric model was presented as hypothetical, the Vatican was unconcerned by Copernicanism. One man changed all that.
Born in February 1564, Galileo Galilei initially set out to be a doctor before switching to mathematics – much to the displeasure of his father. It is unlikely that, according to the legend, he ever dropped balls from the leaning tower of Pisa as he investigated the motion of falling bodies and discovered that all objects fall at the same rate, contradicting what everybody believed since Aristotle.
When, in 1609, he learnt of the invention of the telescope by a Dutch spectacle maker, Galileo quickly constructed his own. Within a matter of months he had transformed it from a toy into an instrument of scientific discovery and he found that the Milky Way was not a streak across the sky but a multitude of stars; that the Moon had mountains and valleys; and he observed the phases of Venus and the spots on the Sun.
'For Galileo, seeing was believing,’ says the historian David Wootton. Yet he argues persuasively in this well researched, intellectual biography that Galileo was a Copernican long before his discovery of the moons of Jupiter proved that not all heavenly bodies revolved around the Earth. In March 1610, Galileo published his discoveries in the aptly titled book, The Starry Messenger. All 550 copies were sold within a week and soon the 46 year-old was Europe’s most celebrated natural philosopher.
Faced with the Reformation, the Catholic Church was increasingly less tolerant of dissent. In 1616, Galileo went to Rome after a letter he wrote was brought to the attention of the Holy Office of the Inquisition. In it Galileo argued that although the Bible is the word of God, it is adapted to human capacities. Nature, however, is 'inexorable and immutable’. So, when it comes to certain questions, direct knowledge of nature must always take priority over whatever the Bible may have to say on the subject. And the answer to one of those questions was that it is the Earth that moves around the Sun and not the other way round.
Wootton does a good job of untangling who said what to whom and when in Galileo’s dealings with the Inquisition. To cut a long story short, Galileo was given a formal warning that forbade him from holding, teaching or defending Copernicanism. To complicate matters, around the same time, in March 1616, the Vatican banned all books that held Copernicanism to be true.
Then, in a surprising turn of events, in 1623 Maffeo Barberini, an old friend of Galileo’s, was elected pope. Urban VIII allowed Galileo to re-enter the somewhat muted debate on Copernicanism. Before long, argues Wootton, intellectual ambition and vanity led Galileo to stake everything on facing down his opponents in his book Dialogue on the Two Chief World Systems. In April 1633, Galileo was summoned before the Inquisition and held firm that, although in the Dialogue he discussed Copernicanism, he did not defend it, and he denied any knowledge of the injunction of 1616 not even to do that.
It was at this point that the prosecutor played his trump card – a report that Galileo was guilty in an earlier book of denying transubstantiation. It was a charge that, if proven, implied that Galileo was not a Catholic but a Protestant. While admitting to piling 'conjecture upon conjecture’, Wootton goes further than any enforcer of the Inquisition and accuses Galileo of not being a Christian at all.
Galileo died in 1642, a prisoner of the Inquisition. In 1992, the Catholic Church apologised for its treatment of the secular saint. Only God knows what Leo X would have made of it all.