How to Support Galileo and Get Away with it

As I note last week, Lucio Russo’s The Forgotten Revolution posits that there was a scientific revolution in around 300BC which, for one reason or another, never took root. Classicists have not really been convinced by this thesis, but his book is interesting nonetheless. One minor mistake that Russo makes is to imagine that natural philosophers in the early seventeenth century associated the heliocentric hypothesis more with the ancient Greek Aristarchus of Samos than with Copernicus. To support this claim he notes a book called The System of the World by Aristarchus of Samos, edited by Gilles de Roberval, which appeared in Paris in 1644. Since I was in the Cambridge University Library while reading Russo, I popped down to the Rare Books Room to have a look at this intriguingly entitled volume.

In the aftermath of Galileo’s trial, stating that the heliocentric hypothesis was true was forbidden in Catholic countries, including France. Although the ban ceased to be policed long before it was actually rescinded, for a few years natural philosophers needed to find more creative ways to get around it. Gilles de Roberval produced one of the more entertaining ones.

Gilles de Roberval was a commoner born near Beauvais who rose to a professorship at the College de France and became one of the country’s leading mathematicians. Although highly competent, he appears to have been a bit of timeserver compared to his illustrious contemporary Rene Descartes. Still, in 1644, he obtained a royal licence for his book espousing heliocentricism at the same time that Descartes decided it was wiser to keep mum on the subject.

Gilles realised that, as a salaried professor in the employ of the king, he could not be openly disloyal to the church. So he used the old trick of pretending that he was saying the opposite of what he actually meant. The System of the World by Aristarchus of Samos purports to be a translation of the Arabic version of a lost treatise of Aristarchus describing his heliocentric hypothesis. But in reality it is all from the pen of Gilles himself, as everyone seems to have known. Gilles appended a forward under his own name where he pretended to be highly sceptical about the thesis he was presenting, even though it was all his own work. He also added some annotation to the text by “Aristarchus” where he praises the author (that is, himself). One note reads “To this we should add the satellites of Jupiter of which the author of this work was unaware.” Yeah right.

Still, the ruse worked. Anyone who was anyone could see through the hoax. But to the general public, Gilles was just bringing to light a lost Greek text, which was perfectly acceptable behaviour for a seventeenth-century scholar. That said, it was all rather undignified and that counts as another reason to regret the stupidity of the Church hierarchy for bringing in the ban on asserting the truth of heliocentric theory in the first place.

Discuss this post at the Quodlibeta Forum