Ebook: Retrying Galileo, 1633-1992

This book is of course valuable as a collection of primary texts. However, Finocchiaro is not content to be an editor and instead interferes frequently and intrusively, and not always very intelligently. For illustration, I shall comment on Finocchiaro's very obtuse dismissal of Koestler's portrayal of Galileo in the Sleepwalkers.

----Fallaciousness of Galileo's tidal argument for heliocentrism.

"The straw-man fallacy is most obvious in Koestler's account of the tidal argument. What he presented was an incoherent piece of reasoning that caricatures the original; but the presentation proves only the superficiality of Koestler's reading, not the fallaciousness of Galileo's reasoning. There is no questions, of course, that Galileo held that the tides are caused by the earth's motion, and that we now know this is not true. But the falsity of a claim cannot be equated with the fallaciousness of the reasoning from which the claim was inferred ... Koestler's evaluation was also anachronistic and wise after the event." (p. 311)

Finocchiaro offers no historical evidence whatsoever for all these accusations. This is especially ironic since he condescendingly speaks of Koestler's book as having "all the trappings of scholarship (references, footnotes, etc.)" (p. 308). For those who care about the actual historical record rather than Finocchiaro's unsubstantiated assertions, it is clear that Koestler's argument is neither a caricature, nor focused on the claim rather than the argument, nor anachronistic, nor wise after the event. Instead, Koestler is simply repeating a standard, accurate critique of Galileo that was raised immediately by Galileo's contemporaries and has stood unanswered ever since:

"[This argument] was expressed as early as 1633 by a group of French physicists, of whom Jean-Jaques Bouchard wrote to Galileo: 'They draw attention to a difficulty raised by several members about the proposition you make that the tides are caused by the unevenness of the motion of the different parts of the earth. They admit that these parts move with greater speed when they descend along the line of direction of the annual motion than when they move in the opposite direction. But this acceleration is only relative to the annual motion; relative to the body of the earth as well as to the water, the parts always move with the same speed. They say, therefore, that it is hard to understand how the parts of the earth, which always move in the same way relative to themselves and the water, can impress varying motions to the water.'" (Quoted from Shea, Galileo's Intellectual Revolution, p. 176)

----Galileo's rhetorical tactics.

"To support his claim that in oral argument Galileo used the shortsighted and ineffective rhetorical tactic of ridiculing an opponent and making an enemy out of him, Koestler quoted [Querengo]: '... What I liked most was that, before answering the opposing reasons, he amplified them and fortified them himself with new grounds which appeared invincible, so that, in demolishing them subsequently, he made his opponents look all the more ridiculous.' The technique that Querengo liked best is actually a very sound, wise, and proper one; it really amounts to being concerned to avoid the straw-man fallacy; that is, before criticising an opponent, it is a sign of serious critic to first strengthen the opposing argument as much as possible and interpret it in the most charitable manner; by so doing, one's criticism will really undermine the argument, rather than destroying one's own caricature invented to make one's own task easy. Despite what Querengo says, in such a situation the opponent is not made to 'look all the more ridiculous' but rather is portrayed as someone who holds plausible arguments and good reasons, which are nevertheless invalid and incorrect. However, Koestler completely overlooked this aspect of Galileo's tactics and instead focused on other aspects that were indeed less effective and more shortsighted. But again, what that shows is Koestler's superficiality and penchant for straw-man reconstructions rather than a real flaw in Galileo's behavior." (pp. 311-312)

The "superficiality" lies entirely with Finocchiaro, who provides no evidence that these platitudes from his Philosophy 101 lectures have any historical basis whatever. Indeed, his reconstruction is even blatantly inconsistent with the very quotation that occasioned it, as Finocchiaro himself admits ("despite what Querengo says..."). If this extravagant reconstruction is accurate, then why not offer some examples of passages where Galileo is concerned with avoiding the straw man fallacy? None are forthcoming. Examples of the contrary, however, abound. An illustrative one is Galileo's famous tirade about Babylonians cooking eggs in slings. To maintain that tirades such as this display "sound, wise, and proper" concern to avoid the straw man fallacy is patently laughable.