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Visiting the Acropolis in 1850, the 29-year-old Florence Nightingale came across boys playing with a baby owl that had fallen from its nest. She bought it from

them, named it Athena (goddess of wisdom), and nurtured it until its death, two days before she sailed for the Crimea with a party of nurses in 1854. Translations of the Middle English 12th-century poem The Owl and the Nightingale appeared when Nightingale was 18 and 23. She is likely to have read with appreciation Owl’s observation that “[when her] lord travels … on behalf of both of them … the good wife is … sad by day and sleepless by night, and the time seems to her to pass very slowly” and Owl’s curt dismissal of the nightingale with “Do you think I can’t sing just because I can’t twitter?”

By 1850, Nightingale already had a vision of something less domestic and less frivolous than twittering! She had embraced Quetelet’s vision of the power of “social physics”—the statistics of today—and understood what could be discovered by col-lecting and tabulating large numbers of observations in almost any area of social activity. She came to see that statistics would give her the knowledge and power to overcome social evils. At least two years before she left for the Crimea, Nightingale’s

The Owl and the Nightingale: The Quetelet/Nightingale Nexus Mervyn Stone

statistical passion was as vibrant and deeply seated as it would be for decades afterward.

There was something about Nightingale’s interpretation of Quetelet’s teaching that gave it a distinctive and person-ally motivating intensity. She was fatalist in the sense that, at bottom, everything was predetermined by causes under God’s will and that, at the level of individual action, free-will was an illusion—there was no room for chance or probability in her cosmic vision. Individual fate could be infl uenced only by soci-ety acting on the causal infl uences and a willing God’s will.

When Quetelet wrote playfully about the “frightful regu-larity” of statistical proportions, it was for him a simple con-sequence of probability doing its work in what we now call the Law of Large Numbers, but Nightingale interpreted the same regularity as a sign of the working out of God’s will. Nightingale did not accept the concept of statistical random-ness in her everyday philosophy. Her belief was that life was not randomly determined, but ordained by a higher agency. This was not a simple-minded misinterpretation of the large number law. The archival evidence suggests Nightingale had to maintain her position by deliberately turning a blind eye to the poetic element that imbues all Quetelet’s writings.

It was also a fruitful misreading in that it motivated Nightingale to use the elements of Quetelet’s statistical method and reasoning in the cause of sanitary reform after the war. In his book Florence Nightingale: Avenging Angel, Hugh Small suggests there may have been another motivation—an overwhelming remorse and guilt from failure to have applied, in the winter of 1854–1855, what her statistical mentor Quetelet had taught her. In other words, a failure to have ‘remembered her Quetelet’ when the number of deaths in the base hospital was mounting so dramatically. After the war, Nightingale may have tortured herself with the realization that she had not gotten her gov-ernment to organize a registration of mortality data—of the sort that later revealed, in registrar-general Farr’s tables, the truth about the frightful and avoidable loss of life on the fl oors of the Scutari barracks hospital. After the war, Nightingale’s misreading of Quetelet may have given her some comfort

Nightingale Quetelet

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throughout the collapse triggered by that realization—by reassuring her that it had been God’s will, not her own free will, that had sent her to the Crimea in 1854 and then delayed her response to the mounting evidence until its cause could be clearly ascertained.

More than 30 years ago, I was asked to refurbish the library of my University College London (UCL) department. The chore turned to cheer when I found something interesting and valuable in a dingy fl oor-level cupboard. It was the two volumes of the second edition of Quetelet’s Physique Sociale of 1869 that he had presented to Nightingale in 1872 and that had her penciled marginalia on many pages. It was a joy and privilege to transcribe the marginalia, which had gone into the cupboard via Francis Galton and Karl Pearson.

My 1981 transcription of the marginalia, together with the minimal explanatory material and a sprinkling of minor errors, fi lls 36 pages of a three-part Royal Statistical Society’s Series A paper. There is also a partial transcription in Volume 5 of Lynn McDonald’s Collected Works of Florence Nightingale, and there may be others. One visitor to the UCL department—she may have been an academic nurse from California—asked to see the 1869 Quetelet (before it went to the safe keeping of UCL archives). She was locked alone with the book in a room and, a little later, a voice from the room was that of her reading something into a Silicon Valley device or the like. When she came out, I did not tell her the room had been one of the fi lm sets of the Egyptian mummy fi lm The Awakening with Charlton Heston in the role of a professor of Egyptology at the British Museum. So, when you see the fi lm again, think Quetelet!

Taking Quetelet at His Word Before the War Nightingale came to admire Quetelet’s achievements not, as some have suggested, from familiarity with his seminal 1835 book Sur l’Homme et le Développement de ses Facultés ou Essai de Physique Sociale, but from some other source. Sooner or later, Nightingale scholars will pin down precisely where, by textual comparison of Nightingale’s writings and Quetelet’s books. There are clues in the unpublished memorial essay Nightingale wrote when she learned of Quetelet’s death in 1874. Half-way through her 1874 “Essay in Memoriam,” there is a footnote in which Nightingale tells us some portion of the essay was written in 1851–1852. The footnote was squeezed onto the page as if it were an afterthought—and so came between two halves of a scathing opinion about the role of free will:

Roughly speaking, man or what he chooses to call [foot-note here] his “free will” is the effect of the causes of his social system. Modify the causes and you modify the man—“free will” and all. (Page 341, Series A paper)

This quotation is almost certainly alluding to the title of Quetelet’s 1848 Du Système Social et des Lois qui le régissent—as is another quotation from the essay:

So far back as 1848, Quetelet said that one would think that it had been determined by Legal Enactment how many Marriages exactly should take place at each different age of the contracting parties: so great is the regularity. Were the fi gure fi xed beforehand, the infrac-tion to the rule could not be fewer. The 'fi gure' is fi xed beforehand: by the condition of Society—by Religious and Social institutions—by the state of Government

and legislation. But this is only to say that the wills or inclinations of men and women will be the same: the same causes acting. It is only to say that the series of general facts by which society exists registers invariable laws. (Page 338, Series A paper)

Just two pages before the footnote (if you ignore a page almost certainly misplaced in the British Library binding of the essay), Nightingale named Quetelet in an inspiring proto-defi nition of our discipline:

Quetelet has discovered something (something of a method and something of facts) capable of inexhaustible application—a true conception and a certain inkling of facts. (Page 340, Series A paper)

Strong evidence indeed that Nightingale was imbued with Quetelet’s own enthusiasm years before she went to the Crimea. She revealed the full extent of Quetelet’s infl uence in the underlining of the following quotations from her 1852 essay, “To the Artizans of England,” which became part of the much longer 1860 essay “Suggestions for Thought”:

Men fear to hear that so precise is law in its results that the number of murders which will be committed next year can be foretold with approximation to accuracy. They think, “Their law says you shall commit those mur-ders.” Law says, “If certain circumstances now existing remain, those murders will be committed. Ye that would not have it so, strive to fi nd out those circumstances in order to alter them.” (Page 33 of the 1852 essay)

The supposition is that each volition consists with, is simultaneous with, or successive to a defi nite state of nature. With this state of the latter will exist that state of the former. Yet we should not use the phrase free will to express this conception. (Page 35)

Nightingale Receiving the Wounded at Scutari, by Jerry Barrett Public Domain, Wikimedia Commons

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Florence NightingaleAdolphe Quetelet

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1796Born in Ghent in the nascent Belgium, mathematician, astronomer, statistician

1819Thesis on conic sections

1820 Born in Florence, Italy, statistician and hospital reformer

1823Founded Brussels observatory

1835Major work, Physique Sociale

1836Tutored future Prince Albert in probability

1841Created Commission centrale de Statistique

1851-1853Studied mathematics at homeMet Babbage, Ada Lovelace, HerschelStudied hospitals over Europe

1854-1856 At the Scutari hospital in Crimean War

1855A debilitating stroke

1856 Founded Nightingale NursesWork with Benjamin Farr for Royal Commission on High Crimean MortalityTook to her bed

1859 Major work, Notes on Hospitals

1860 Met Quetelet for British Association

1872Gave Nightingale 2nd edition of Physique Sociale

1874 Essay In MemoriamDied in Brussels

1910 Died in London

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Nightingale’s mathematical bent and her ability to extract the sense of the at-hand Herschel and the French translation Quetelet used as the introduction to his 1869 edition:

Postulates1. Probability of compound event AB = probability of A � probability of B (its constituents)2. Law of relation between amount and probability of error / Regular Law of Progression3. Equal probability of equal errors

The text of the original Herschel review shows this anno-tation is an accurate, even if not very informative, précis of Herschel’s outline axiomatic characterization of the circular bivariate normal. The symbols A, B, and AB were Nightingale’s own shorthand.

The page references for the following exchanges between Quetelet’s text and Nightingale’s here-italicized marginalia are to the 1981 Series A transcription:

For Quetelet, providence is the cancellation of positive and negative errors that generates frightful regularities, by working through secondary causes and contin-gencies. For Nightingale: “Providential arrangement is the ‘arrangement’ of ‘secondary causes and contingencies.’ What else can it be?, and ‘Errors’ even are by ‘arrangement.’” (Page 179)

For Quetelet, those ‘frightful regularities’ are pre-sented as appearing to deny free will and choice. For Nightingale, it is not just appearance:

Blunder again as to free will and choice. Man’s “will” is determined by the “acting causes” of his “social system.” Alter these and his will is altered. (Page 183).

Nightingale is keen to control the appearances:

Alter the causes. Mankind can govern by laws moral as he does by laws physical, but mankind can discover the laws—and govern by their means. (Page 186)

Quetelet saw statistical regularities as the series of gen-eral facts by which a society exists and is preserved—a subtlety Nightingale takes to mean that the intention of God is not that mankind, ignorant mankind, can have an eternal or infi nite action: at his own caprice. How unjust if it were so. God alone sets the limits (i.e., the laws). We act within his laws—under his laws—and also by his laws. God governs by his laws—but so do we—when we have discovered them. … This only means that the general will produces the causes of which the individual wills are the effects. But the general will can be modifi ed. (Page 187)

Quetelet observes that tables of mortality do not determine when any particular individual will die. Nightingale is happy to see that there is hence no fatalism in these calculations [my underline], while still maintaining that individual wills are the effects of causes on which society can exercise its free will. (Page 189)

For Quetelet, small samples of data do not give the degree of probability one needs to be confi dent in one’s conclusions—which prompted Nightingale to ask: What is probability? (Page 189)

If the existence of universal law be granted, then remorse is not a true feeling—not a feeling of what really is, for remorse is blame to ourselves for the past. But if the origin of our will, and our will itself, were, as it has been, in accordance with law, there cannot, in truth, be blame to ourselves, personally, individually. (Page 44)

To a healthy moral nature, having on an occasion erred, it would be as impossible to be indifferent to that error, though he should believe that it had not been in his possibility to avoid it, as it would be to one who should receive a bodily wound to be indifferent because it was not his fault. We object to saying that a man could not have willed otherwise than he did, because this sounds as if he would or might have willed otherwise, but was under necessity through other power. We mean that the conditions on which will depends were such that, law being what it is, it was not possible that other will than that which did exist should exist. (Page 45)

Here, this extraordinary 32-year-old woman is making everything crystal clear. She was not committing a proba-bilistic howler when she thus interpreted Quetelet’s poetic use of phrases such as “frightful regularity.” She was simply stating her belief that, at a deeper level that she identifi es elsewhere as God’s will, there is no such thing as chance and probability has no role. At bottom, everything in the world is predetermined—and “remorse,” too, has no place in the scheme of things. However, her phrase “approximation to accuracy” may indicate she had some concern about the deviations from “frightful regularity” that occur even when “circumstances” appear to be the same. Was God, too, she may have wondered, going to sleep on the job?

Taking Quetelet at His Word After the War Quetelet suffered a stroke in 1855, and his 1869 Physique Socialewas, in the main, an inferior rearrangement of materials drawn from the fi rst edition. Unfamiliar with the latter, Nightingale accepted Quetelet’s gift of the book as an entirely new work and could not have made the comparison of quality we are free to make. The 1869 edition has a long introduction—a translation of Sir John Herschel’s review of O. G. Downes’s 1849 English translation of Quetelet’s 1846 Lettres à S.A.R. le duc régnant de Saxe-Coburg et Gotha. Nightingale’s fi rst marginal note was a reference—Edinburgh Review No 185 July 1850 Sir John Herschel—that she placed next to the text’s own reference to the review, which itself was a reference to its 1857 reprint in Essays from the Edinburgh and Quarterly Review. The marginalia reveal Nightingale had the Herschel review to hand when she was annotating—either the 1850 original review or its 1857 reprint. Nightingale’s marginal note suggests it was the former, in which case she may well have read it, reinforcing Quetelet’s infl uence, when she got back to her Lea Hurst home from the Acropolis in August of 1850, well before her Crimean engagement.

The Chasm Between Quetelet’s Playful Poetry and Nightingale’s Fatalistic Philosophy Before documenting the marginalia that highlight the chasm, here is a remarkable item from the margins. It reveals

34 VOL. 24, NO. 4, 2011

Quetelet says that it is in marriage that free will is most active, which Nightingale simply rebuts with: But one can only say that the inclinations, wills of men and women will be the same: the same causes acting. (Page 197)

When Quetelet claims that marriage statistics are, nev-ertheless, more regular than “physical laws” and “Earth’s productions,” Nightingale expresses agreement with: Not the arrangement of chance. (Page 198)

When Quetelet says the possibility of establishing a moral framework for statistics depends on the fact that free will is effaced when you observe a large number of individuals, Nightingale is scathingly blunt: Is not this nonsense? Is it not rather (what he says in the next sentence) that the man (or what he chooses to call his ‘Libre arbitre’) is the effect of the causes (the ‘Système Social’)? Modify the causes and you modify the man—‘Libre arbitre’ and all. (Page 208)

Crossing a Tiny Disciplinary Divide These Nightingale marginalia are evidence of deep disagree-ment with Quetelet about where free will should be located between individuals and society. It was evidence that Marion Diamond and Mervyn Stone overlooked in 1981 and that historians Michael Calabria and Janet Macrae bypassed in their 1994 book, Suggestions for Thought by Florence Nightingale: Selections and Commentaries: “Unlike many of their contempo-raries, Quetelet and Nightingale felt that human will is subject to law, as is everything else in the universe.”

Lynn McDonald’s Collected Works Vol. 5 suggests it is a matter of emphasis:

She [Nightingale] disagreed with his statement about God wanting to limit attacks on his laws, even calling it “nonsense” … immediately going on to Quetelet’s better expression of free will and law. (See Page 208, Series A paper)

Quetelet’s playfulness about free will was openly admitted in the Herschel introduction that Nightingale annotated in its French translation:

This singular result (says M. Quetelet) always astonishes persons unfamiliar with this kind of research. How, in fact, can it be believed that errors and inaccuracies are committed with the same regularity as a series of events whose order is calculated in advance? There is something mysterious, which ceases to surprise, when we examine things more closely. (Page 179, Series A paper)

The underlining was made by Nightingale (in the French text)—not, I suggest, to indicate agreement with Quetelet, but to show she was determined to hold him to his word and that she, at least, could provide the necessary belief. Did Quetelet sense the longstanding gulf between them on this issue when they met in 1860 over breakfast in her suite in the Burling-ton Hotel? Quetelet, at 64, was attending the International Statistical Congress to which Nightingale, at 40 and just elected fi rst female fellow of the Statistical Society of London, had submitted a paper on sanitary reform.

Nightingale scholarship and statistical science may have to join forces if they are to fi nd any consensus on the question. There is, however, one bit of the disciplinary divide that is easily bridged. In an endnote to his fi ne biography, Florence Nightingale: The Woman and Her Legend, Mark Bostridge tells readers to go to the Diamond and Stone Series A paper for a discussion of Nightingale’s relationship to Quetelet and adds to the gaiety of life by directing them in his bibliography to the Series A of a nonexistent Journal of the Royal Historical Society.

A Royal Statistical Society meeting in October 2010—The Passionate Statistician: Florence Nightingale’s Use of Statistics and LinksWith Statisticians—touched on the substantial issue of whether it was physical sickness or mental stress that triggered Nightingale’s retreat to her bed one year after the end of the Crimean War. This paper has unearthed evidence for one side of the dispute. The evidence adds a plausible supposition of statistical guilt to Nightingale’s idiosyncratic interpretation of the colorful words Quetelet used to draw attention to the property of random sequences that is the Law of Large Num-bers. We conclude that close analysis of the archival material has thereby thrown new light on the complex relationship of these two remarkable individuals.

Further Reading

Diamond, M., and M. Stone. 1981. Nightingale on Quete-let. I: The passionate statistician. II: The marginalia. III: Essay in memoriam. J. Roy. Statist. Soc. Series A 144:66–79, 176–213, 332–351.

Nightingale, F. 1874. Essay in memoriam. London: Private, BM Add. MS 45842, ff.142–200 excluding f.166; tran-scribed as Part III of Diamond and Stone.

Nightingale, F. 1852. To the artizans of England. London: Private, British Library, Cup 401 i 8.

Stone, M. 1988. Quetelet and the poetry of statistical con-jecture. CHANCE 1:10–16.

Wessex Parallel Web Texts. 2003. The owl and the nightingale. University of Southampton, www.soton.ac.uk/~wpwt/trans/owl/owltrans.htm.