Toward a history of “eppur si muove”

Here I want to offer something of a history of Galileo’s unverifiable “eppur si muove.” My last post was not particularly helpful because it did not elevate the level of the discussion. I hope this post will contribute to a conversation about history and its uses. There is more at issue here than me just being an “overly literal type.” I worry that too many of readers won’t recognize why the sentiment and the quotation were ascribed to Galileo or the work the quotation does in our story of science and it’s relationship to non-science (society, politics, religion, etc.).

There is a the painting attributed to B. E. Murillo or somebody in his school in Madrid that represents Galileo in prison. When cleaned, in 1911, it turned out that the painting was larger than originally framed. When unfolded, it revealed that the figure of Galileo was gesturing toward the words “eppur si muove.” The painting seems to have been commissioned by Genreal Ottavio Piccolomini in Madrid, sometime between 1643 and 1650. John Heilbron, in his recent biography of Galileo, Galileo (OUP, 2010), associates the statement with Archbishop Ascanio Piccolomini, who had supported Galileo and his work, and with whom Galileo spent some months after his trial. Archbishop Piccolomini had few friends in the Vatican and continued to annoy the Church hierarchy by reportedly providing a safe place for Galileo to discuss his opinions. The Church grew tired of the archbishop’s sympathy for Galileo and ordered him removed from the archbishop’s residence in Siena (see Heilbron pp. 325–327).

There is, then, some evidence that the thought “And yet it moves” was ascribed to Galileo in the mid-seventeenth century, at least in Madrid perhaps by one of the Piccolomini brothers who was unhappy with the Church. But that does not constitute evidence that Galileo said those words. The standard account attributing this expression to Galileo derives from Stillman Drake’s Galileo at Work (Chicago, 1978), 356–357. There, Drake tells us that

[n]othing would have been more in character for Galileo, at the moment of leaving the hospitality of his good friend and host Ascanio Piccolomini, than—just before entering the waiting carriage—to stamp a foot on the ground, perhaps wink, and utter the famous words (357).

I confess that I would prefer stronger evidence for Galileo having said “eppur si muove” than Drake’s colorful recreation of the scene and his qualified assurance that “[q]uite possibly the story, which could not be circulated widely with safety to Galileo, was passed on within the [Piccolomini] family” and “[t]hereafter it lived on in oral tradition” before being “[p]rinted a century later” (357).

I have no doubt that Galileo continued to believe that the earth orbited the sun—his subsequent work bears witness to his conviction. But ascribing a sentiment to a person is different from attributing a quotation to that person. The painting, pace Drake, does not warrant putting the words into Galileo’s mouth. Nor does Giuseppe Baretti’s account from 1757, which “remains apparently the first statement of the myth” (M. Finocchiaro, Retrying Galileo (Berkeley, 2005), 114). Baretti, like Ottavio Piccolomini, was living in a foreign country where he could safely express his own displeasure with the Church.

It is not accidental that scientists and other non-historians repeat the story as if it is true. Perhaps the most famous is Stephen Hawking, who simply asserts in his recent book On the Shoulders of Giants: “Some historians believe that it was upon his transfer that Galileo actually said ‘Eppur si muove,’ rather than at his public abjuration following the trial” (p. 397). People too readily assume that because Hawking is a famous scientist he speaks the truth. Such an assumption, however, depends on an argument from authority. In this particular case, however smart and accomplished Hawking is, he is not a historian. His expertise in cosmology and theoretical physics does not confer expertise in history. Expertise is not fungible. Hawking lacks historical expertise and, consequently, authority in historical matters (for more on historical expertise, see here, here, here, here and here). Indeed, his On the Shoulders of Giants is not a work of history but rather, as the title suggests, a genealogy of science. Like all genealogies, it tells a triumphalist and therefore selective story about how the present came to be. Hawking has populated his book with the past scientists who, to his mind, have contributed to his science (for some of the problems with that, see my earlier post or either of Thony’s posts). Notably, Hawking included Galileo’s Dialogues Concerning Two New Sciences but nothing from Galileo’s astrology or his work on tides. This other material was probably excluded because either it is no longer science, as in the case of astrology, or Galileo got it wrong, as in the case of tides.

I would like to think that all reasonable readers recognize the Galileo story as probably apocryphal. However, as Hawking’s quotation above indicates, reasonable readers don’t consider “eppur si muove” as apocryphal—Hawking’s own formulation implies that the question is not if Galileo said “eppur si muove” but when Galileo said it. I think many reasonable people understand the story as having considerable truth in it. Examples of it being repeated by reasonable and educated people are easy to find. For example, even on such a science oriented blog as the Panda’s Thumb a commenter can invoke the Galileo myth apparently with full confidence that it is true; the Galileo Press, “a leading international publisher for computer and SAP books,” celebrates this story as a fact: “ Eppur si muove, (and yet it moves), he [Galileo] famously said after being forced to recant his heretical theory that the earth moves around the sun.” My concern seems to be shared by at least one other historian of science. In his recent biography of Galileo, Heilbron clearly thinks that most reasonable readers still need to be told that Galileo did not, in fact, say “still it moves:” “Galileo rose without muttering eppur si muove (“still it moves”) and returned, shattered, to the Medici palace” (p. 317).

We might argue about how much truth and how many readers and what constitutes reasonable, but given the problematic nature of the story, I think it calls for some qualification, some acknowledgement of or indication that the story is a myth or apocryphal or at least subject to debate. An explicit invocation of a literary adaptation of Galileo’s trial would also prevent confusion. Alluding to Andrea Sarti’s pleasant little tune, for example, would make clear that the reference should not be taken as historical fact but as fiction that aptly captured some sentiment:

The Bible proves the earth stands still,
The Pope, he swears with tears:
The earth stands still. To prove it so
He takes it by the ears.
And gentlefolk, they say so too.
Each learned doctor proves
(If you grease his palm): The earth stands still.
And yet—and yet it moves.
(B. Brecht, Galileo, Scene 8.)

Why does all this animate me so? At one level, I see in this yet another denial of historical expertise. Attributing to Galileo a statement for which there is no evidence suggests that what might or might not have happened and what might or might not be demonstrable according to the standards that govern the practice of history is irrelevant. Closely related to this concern is another about evidence. The problem in North Carolina seems to be that the legislature was considering passing a law that ignored relevant evidence, limited who could present evidence, and stipulated how evidence could be treated. If we are criticizing somebody for playing fast and loose with the evidence, it seems we have an obligation to be particularly careful what information we elevate to the level of evidence and how we use that evidence. At another level, along with their other functions myths serve to validate and reassert existing social orders and limit enquiry by making those social orders seem right, natural, and inevitable. If we are intellectually honest, in denying to Christians the validity of their creation myths because we see no evidence supporting those myths and can point to evidence that seems to deny them, shouldn’t we also deny validity to scientific myths when they lack supporting evidence and when we can point to evidence that seems to deny them? The deployment of questionable, apocryphal, or mythical information is never neutral or incidental. It always serves certain knowledge making and propaganda efforts.
[Reposted at PACHS.]