Galileo

Galileo's Daughter: A Drama of Science, Faith and Love

By Dava Sobel

Fourth Estate, 2000

429 pp., $22.95 (pb)

Review by Phil Shannon

http://www.greenleft.org.au/node/21169

The verdict was "vehemently suspected of heresy" for holding the false doctrine, "contrary to Holy Scripture", that the Sun, not the Earth, is the centre of the universe. To avoid execution, he must "abjure, curse and detest" the heresy. The sentence was imprisonment in the dungeons of the Holy Office of the Inquisition.

As Galileo, the great Italian scientist who founded modern physics in the 17th century, rose from his knees after making the required humiliation to his Catholic judges, he is said to have muttered under his breath, "But still it moves". The thought-control police of the Inquisition could not stop the Earth from orbiting around the Sun, or Galileo from believing it.

The stirring drama of Galileo Galilei's unrepentant fealty to science and human reason in the face of ecclesiastical dogma and power is one of the inspiring moments in the history of science, a crucial challenge to religious authority that made possible the march of progress.

Dava Sobel has revisited the Galileo story in her new book. Born in 1564 to the intelligentsia in Italy, Galileo became a mathematics professor. Knowing the value of an influential patron, especially when dealing with heretical ideas like the heliocentric (Sun-centred universe) theories of his predecessor, the Polish cleric Nicolaus Copernicus, Galileo sought a court post as philosopher and mathematician to the Grand Duke of Tuscany. He eventually found security under this wing of the powerful Medici family of Florence in 1610.

Galileo, long sympathetic to Copernican theories, had turned his marvellous invention, the telescope, to the heavens in 1609. What he observed of sunspots, stars and planetary movements confirmed the ideas of Copernicus, and Galileo now felt safe enough to commit his views to paper.

This was, however, a dangerous time to be advocating ideas which conflicted with church doctrine in Italy. Stung by the Protestant split a century earlier, the Catholic Church had tightened its control over its flock.

Galileo's first brush with the heresy-hunters of the Inquisition had come in 1616, when he was warned not to entertain Copernican theories and not to attempt to square heliocentrism by any interpretation of the Bible other than the approved one.

Galileo acquiesced but, seven years later, he resumed his work on heliocentrism following the ascension of a new pope in 1623. Pope Urban had a liberal tinge and held out hope to scientists for more intellectual freedom. Urban gave his blessing to Galileo to resume his studies, provided that he treat heliocentrism as hypothesis not fact.

Galileo proceeded to write his most famous book, Dialogue on the Two Chief World Systems, which, in an easily accessible dialogue style, pitted proponents of the Earth-centred and Sun-centred systems head to head. Formally sceptical of heliocentrism in his summing up (to conform with the pope's instructions), Galileo's book passed the censors for publication. However, as soon became obvious to all, the Copernicans, including Galileo's many enemies, had the best of the arguments in the book. The pope, accused of flagging Catholic zeal on the anti-Protestant battle-fronts of Europe, turned against this new threat.

Summoned to Rome in 1633, the ailing 70-year-old Galileo renewed acquaintance with the Inquisition. There were to be no second chances this time. Under threat of torture and death, Galileo was forced to recant his heliocentric views and sentenced to prison "as an example for others to abstain from delinquencies of this sort".

His sentence was commuted, after intercession from influential friends, to house arrest and he spent the last nine years of his life confined to his villa in Arcetri, near Florence, forbidden from writing and teaching, his books all banned.

News of Galileo's silencing spread widely, as did copies of his book, smuggled across the Alps, which became a prize possession of scientists and supporters of Galileo, such as Rene Descartes, Pierre de Fermat, John Milton and Thomas Hobbes. Galileo's last and equally important book on mechanics and motion was also smuggled out of Italy.

By writing and smuggling out his books, Galileo showed he had not given in to church authority. In 1600, the 36-year-old Galileo would have known of the burning at the stake in Rome of the Dominican friar, Giordano Bruno, for not renouncing heliocentrism. In this volatile religious climate, Galileo adroitly kept one step ahead of the clerical state, staying alive by denouncing Copernican heresy when required by his Inquisitors, yet communicating his real views to his peers.

Sobel's book skilfully captures the tension of Galileo's battle with the Inquisition and the author's grasp on the scientific issues is thorough and fluently communicated.

Less impelling is her literary device of weaving the letters between Galileo and his illegitimate daughter, the nun Suor Maria Celeste, into the story. They show Galileo as a sensitive and loving father but add little to the main conflict.

Neither is Galileo's tussle with the Inquisition situated in its full ideological and political-economic context. The social order of Europe in the Middle Ages was justified by the Catholic Church's exposition of the philosophy of Aristotle, which gave everything in the world a fixed purpose and a fixed place. The universe and the feudal order were both fixed by god. The Earth stood still and all people, from kings to serfs to the growing bourgeoisie, were fixed in their rightful place. Motion, or change, was abnormal.

This ruling ideology was rocked by Galileo's telescope, his book on heliocentrism and his book on a new physics which identified motion and change as the natural order of things. Although Galileo did not make the inference from the world of things to the world of social classes, others did, like Milton, the poet and revolutionary bourgeois democrat, and Hobbes, the bourgeois political philosopher. Others, like the peasant majority of humanity, might.

Although Galileo the good Catholic saw no schism between science and religion, the god he believed in was a god pushed further away from day to day control of events in the world, which could instead be explained by material (and social) forces, not by heaven. With god elbowed to the sidelines, the church as interpreter of god's will and beneficiary of divine power stood exposed as a reactionary social institution, monopolising power, at least to the literate traders, merchants, artisans and manufacturers, the economically strong but politically weak classes which read Galileo in the language he wrote — Italian. To the church, Galileo posed a serious challenge to their control over the "common people", a threat worthy of torture and burning at the stake.

Sobel doesn't develop this materialist dimension and is content to assert that the Galileo-Inquisition struggle was not a "simplistic" struggle between science and religion (or the social forces allied to them), but an example of how science and religion, reason and faith can be on the same team: Galileo was both scientist and Catholic. Sobel even absolves the church from censure: "technically" the Congregation of the Index (the church censors) and the Inquisition were to blame, not the church or the pope. Which is rather like arguing that it was the literary police and political police who were responsible for the silencing and murder of the anti-Stalinist opposition in Soviet Russia, not Stalin or the bureaucratic party-state of which the police bodies were an integral part. This was a church, let us not forget, which didn't rescind Galileo's trial verdict until the end of the 20th century.

Nevertheless, what emerges strongly from Sobel's book is Galileo's brave, wily and successful challenge to religious authority, one that science and humanity will remain indebted to for as long as there is a Sun for the Earth to orbit around.