If Aristotle were alive: Galileo and the Jesuits

16096Today, we have a guest post from Eva Del Soldato, Associate Professor of Romance Languages at the University of Pennsylvania and author of Early Modern Aristotle: On the Making and Unmaking of Authority, new from Penn Press. In Early Modern Aristotle, Del Soldato contends that because the authority of Aristotle—like that of any other ancient, including Plato—was a construct, it could be tailored and customized to serve agendas that were often in direct contrast to one another, at times even in open conflict with the very tenets of Peripatetic philosophy. Here, she explores this argument through the lens of one particular instance: the story of Galileo Galilei, and the often simplistic way we have understood it from a contemporary vantage point.

If history were made of unmistakable heroes and villains, things would certainly be easier for those who try to interpret it. Yet, it is rarely the case, even if biases and ideologies often succeed in popularizing this kind of simplified historical outlook. The tragedy of Galileo Galilei (1564-1642) is a case in point: on one side is the noble scientist, rebel against the constraints of tradition, on the other are his fiercest enemies, the obscurantist Jesuits who made him into a secular martyr for science (if such a thing can be said to exist). On one side Galileo ridiculing Aristotle, on the other the Jesuits still blindly worshipping his authority.

This uncomplicated plot would probably be great for a Netflix series, but it has been debunked by scholarship. Above all, because the Jesuits have been rehabilitated, and it is now widely acknowledged that the order was open to experimental inquiry and that a number of its members made important contributions to science. Between the end of the sixteenth century and the beginning of the seventeenth, the Jesuit Collegio Romano (a school founded by Ignatius of Loyola himself) was a hub of astronomical research. Galileo himself exchanged ideas with Jesuit scholars, and admired their work.

A breaking point between Galileo and the Jesuits was undeniably Galileo’s rejection of the traditional Aristotelian cosmology. Yet, the Jesuits were far from blindly accepting of everything they read in the ancient philosopher. On the contrary, they were ready to challenge him on crucial aspects of the doctrine defended in On the Heavens, such as the solid, crystalline nature of the heavens, disproven by the observations of comets and supernovae. The fluidity of the heavens implied in many ways that they were subject to change and, therefore, corruptible. Admitting the corruptibility of the heavens was, however, a sort of knockout punch to Aristotelian cosmology, and therefore a bridge too far for many of these Jesuit scientists.

The observation of spots on the surface of the sun was, according to Galileo, an irrefutable proof of the corruptibility of the heavens. So irrefutable, the scientist claimed in several circumstances, that even Aristotle, if he were alive, would have been persuaded to revise his doctrines and welcome Galileo as his most faithful follower. To support this argument Galileo strategically presented Aristotle as a hero of empiricism, but also relied on a specific textual foothold: a passage in On the heavens, in which Aristotle claimed that one of the reasons why he did not believe there was corruption in the heavens, was because no one – including him – had ever seen it. Yet, Aristotle did not have a telescope. Thanks to this novel instrument, Galileo had been able to see the sunspots and observe other imperfections in the heavens. To him, it was obvious that a reborn Aristotle would have gladly admitted to being wrong and corrected his theories to reflect the kind of observations made possible by the telescope.

Galileo’s first argument over sunspots (1612) was with a Jesuit scientist, Christoph Scheiner (1573-1650). Initially Scheiner did not accept Galileo’s observations: the spots are not on the surface of the Sun, he argued, but rather were starlike bodies encircling the Sun. This solution allowed him to preserve the Aristotelian incorruptibility of the heavens. A few years later, nonetheless, Scheiner fully embraced celestial corruptibility. The Jesuit Scheiner noted, at that point, that the corruptibility of the heavens is in harmony with the Christian idea of creation (Aristotle instead associated incorruptibility with the eternity of the world). The conclusion? Summoning, like Galileo did, a reborn Aristotle: if Aristotle were alive, he would be a Christian, and as such he would support the celestial corruptibility revealed by the telescope. The same line of argument, including the counterfactual imagining of an Aristoteles redivivus, was appropriated also by another Jesuit scientist, Melchior Cornaeus (1598-1665), who adapted the conversion of the Greek philosopher to his own ends: religious and scientific.

So what happened here? What lay behind the use of “if Aristotle were alive” made by Galileo and by these Jesuit scientists? In spite of the similar context in which the imagining appears, we are indeed in presence of two very different stories. For Galileo, invoking a reborn Philosopher was a way of subtly attacking his adversaries, while casting himself as someone eager to respect the tradition embodied by Aristotle, the auctor par excellence. But at the end of the day, Galileo wanted Aristotle’s endorsement in order to legitimize his rejection of the Aristotelian cosmology. Paradoxically, Galileo was aware that he needed Aristotle’s authority to destroy Aristotelianism. For the Jesuits, this dismissal was not possible: Aristotle could not be cast aside; however, he could be gently corrected and revised. From this perspective, Galileo provided the Jesuits with an extraordinary rhetorical device that they adapted to their needs: imagining a reborn Aristotle, open to reconsidering his ideas in light of what he did not know during his life, permitted them to justify both his paganism and the limited technical means he possessed with which to make his observations. Aristotle’s authority could therefore be kept alive: it was not his fault if he lacked a telescope, and, more crucially, if he was born before the time of Christian revelation.

These scientific debates were not the only instance in which the exercise of imagining what Aristotle would have said, had he been alive, was applied during the early modern period. We also find the very same thought experiment used to address issues of logic, of natural philosophy, of poetry and philology.  And indeed, as long as there was the need to call Aristotle back from the netherworld, it was proof that his authority had still something to say.

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