James Lind (1753), A treatise of the scurvy – key excerpts

Excerpts from the Lind (1753), with help on the ye olde English from others who have quoted him (Hughes, 1975; Bartholomew, 2002; Weber & De Vreese, 2005).

Lind’s study is sometimes presented as an RCT, but it’s not clear how his patients were assigned to groups, just that the cases “were as similar as I could have them” (see discusison in Weber & De Vreese, 2005). Bartholomew (2002) argues that Lind was convinced scurvy was a disease of the digestive system and warns against quoting the positive outcomes for oranges and lemons (and cider) out of the broader context of Lind’s other work.

Here’s what Lind said he did:

“On the 20th May, 1747, I took twelve patients in the scurvy on board the Salisbury at sea. Their cases were as similar as I could have them. They all in general had putrid gums, the spots and lassitude, with weakness of their knees. They lay together in one place, being a proper apartment for the sick in the fore-hold; and had one diet in common to all, viz., water gruel sweetened with sugar in the morning; fresh mutton broth often times for dinner; at other times puddings, boiled biscuit with sugar etc.; and for supper barley, raisins, rice and currants, sago and wine, or the like.”

Groups (n = 2 in each):

  • “ordered each a quart of cyder a day”
  • “twenty five gutts of elixir vitriol three times a day upon an empty stomach, using a gargle strongly acidulated with it for their mouths.”
  • “two spoonfuls of vinegar three times a day upon an empty stomach”
  • “a course of sea water”
  • “two oranges and one lemon given them every day. These they eat with greediness”
  • “The two remaining patients took the bigness of a nutmeg three times a day of an electuray recommended by an hospital surgeon made of garlic, mustard seed, rad. raphan., balsam of Peru and gum myrrh, using for common drink barley water well acidulated with tamarinds, by a decoction of which, with the addition of cremor tartar, they were gently purged three or four times during the course”

Excerpt from the study outcomes:

  • “The consequence was that the most sudden and visible good effects were perceived from the use of the oranges and lemons; one of those who had taken them, being at the end of six days fit for duty”
  • “Next to the oranges, I thought the cyder had the best effects”

References

Bartholomew, M. (2002). James Lind’s Treatise of the Scurvy (1753). Postgraduate Medical Journal, 78, 695–696.

Hughes, R. E. (1975). James Lind and the cure of Scurvy: An experimental approach. Medical History, 19(4), 342–351.

Weber, E., & De Vreese, L. (2005). The causes and cures of scurvy. How modern was James Lind’s methodology? Logic and Logical Philosophy, 14(1), 55–67.

No one else can feel it for you

“I want to know what it is like for a bat to be a bat. Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate to the task” (Nagel, 1974).

“Feel the rain on your skin, no one else can feel it for you” (Bedingfield, 2004).

Prof Eve L. Ewing – “Why I capitalise White”

“Many Black people I know say that they capitalize Black as a show of respect, pride, and celebration, and they don’t want to afford the same courtesy to Whiteness. But we frequently capitalize words for reasons other than respect – words like Holocaust, or Hell […]. When we ignore the specificity and significance of Whiteness – the things that it is, the things that it does – we contribute to its seeming neutrality and thereby grant it power to maintain its invisibility.”
– Prof Eve L. Ewing (2020), I’m a Black Scholar Who Studies Race. Here’s Why I Capitalize ‘White.’

The Positivist Dispute in German Sociology

One of my favourite examples of pointless debate is published in the 300 page, The Positivist Dispute in German Sociology. A big chunk of the debate is people attacking Popper’s positivism. Popper’s withering response notes that he wrote a book criticising positivism:

“This is an old misunderstanding created and perpetuated by people who know of my work only at second-hand: owing to the tolerant attitude adopted by some members of the Vienna Circle, my book, Logik der Forschug [The Logic of Scientific Discovery], in which I criticized this positivist Circle from a realist and anti-positivist point of view, was published in a series of books edited by Moritz Schlick and Philipp Frank, two leading members of the Circle; and those who judge books by their covers (or by their editors) created the myth that I had been a member of the Vienna Circle, and a positivist. Nobody who has read that book (or any other book of mine) would agree – unless indeed he believed in the myth to start with, in which case he may of course find evidence to support his belief.” (Popper, 1976, p. 290)

Popper K. (1976) Reason or Revolution? In T. W. Adorno, H. Albert, R. Dahrendorf, J. Habermas, H. Pilot, & K. R. Popper, The Positivist Dispute in German Sociology (pp. 288–300). Heinemann Educational Books.

Counterfactual analysis as fatalism

‘Many counterfactual analyses are based, explicitly or implicitly, on an attitude that I term fatalism. This considers the various potential responses \(Y_{i}(u)\), when treatment \(i\) is applied to unit \(u\), as predetermined attributes of unit \(u\), waiting only to be uncovered by suitable experimentation. (It is implicit that the unit \(u\) and its properties and propensities exist independently of, and are unaffected by, any treatment that may be applied.) Note that because each unit label \(u\) is regarded as individual and unrepeatable, there is never any possibility of empirically testing this assumption of fatalism, which thus can be categorized as metaphysical.’

– Dawid, A. P. (2000, pp. 412-413) [Causal inference without counterfactuals. Journal of the American Statistical Association, 95, 407–424].

Counterfactual talk as nonsense

‘We all indulge, in anger and regret, in counterfactual talk: “If they had not operated, John would be alive today”; “If I had not said that, she would not have left me”; “If I had chosen a different publisher, my book on causality without counterfactuals would have sold 10,000 copies.” The more fortunate among us have someone to remind us that we are talking nonsense.’

– Shafer, G. (2000, p. 442) [Causal inference without counterfactuals: Comment. Journal of the American Statistical Association, 95, 438–442].

 

“Use the difficulty”

Michael Caine talking about rehearsing a play where other actors improvising had got carried away.

“They started throwing things, and he threw a chair, and it lodged in the doorway. And I went to open the door, and I got my head around, and I went [to the director], ‘I’m sorry, sir, I can’t get in.’

“He said, ‘What do you mean?’

“I said, ‘There’s a chair there.’

“He said to me, ‘Use the difficulty.’

“I said, ‘What do you mean?’

“He said, ‘Well, if it’s a comedy, fall over it. If it’s a drama, pick it up and smash it. Use the difficulty.’”

“… it is time to bring the subject of reparations firmly to the fore”

“It is time to acknowledge openly that much of Europe and the United States have been built from the vast wealth harvested from the sweat, tears, blood and horrors of the trans-Atlantic Slave Trade and the centuries of colonial exploitation. Maybe we should also admit that it cannot be easy to build confident and prosperous societies from nations that, for centuries, had their natural resources looted and their peoples traded as commodities.

“For centuries, the world has been unwilling and unable to confront the realities of the consequences of the slave trade, but gradually this is changing, and it is time to bring the subject of reparations firmly to the fore. Granted that current generations are not the ones that engaged in the slave trade, but that grand inhuman enterprise was state-sponsored and deliberate; and its benefits are clearly interwoven with the present-day economic architecture of the nations that designed and executed it. Reparations must be paid for the slave trade. No amount of money will ever make up for the horrors, but it would make the point that evil was perpetrated, that millions of productive Africans were snatched from the embrace of our continent, and put to work in the Americas and the Caribbean without compensation for their labour.

“If there are any hesitations in some minds about the paying of reparations, it is worth considering the fact that, when slavery was abolished, the slave owners were compensated for the loss of the slaves, because the human beings were labelled as property, deemed to be commodities. Surely, this is a matter that the world must confront, and can no longer ignore.”

Speech by President of the Republic of Ghana, Nana Addo Dankwa Akufo-Addo, at the 78th Session of the United Nations General Assembly, UN Headquarters, New York, Wednesday 20th September 2023

Inside every matching study

A potentially useful one-sentence(!) intervention for making a case to run a statistical matching evaluation rather than a randomised controlled trial:

“Matching can be thought of as a technique for finding approximately ideal experimental data hidden within an observational data set.”

– King, G., & Nielsen, R. (2019, p. 442) [Why Propensity Scores Should Not Be Used for Matching. Political Analysis, 27(4), 435–454]

 

Carol Fitz-Gibbon (1938 – 2017), author of first description of theory-based evaluation, on importance of RCTs

“[…] I produced the first description of theory based evaluation […]. The point of theory based evaluation is to see, firstly, to what extent the theory is being implemented and, secondly, if the predicted outcomes then follow. It is particularly useful as an interim measure of implementation when the outcomes cannot be measured until much later. But most (if not all) theories in social science are only sets of persuasively stated hypotheses that provide a temporary source of guidance. In order to see if the hypotheses can become theories one must measure the extent to which the predicted outcomes are achieved. This requires randomised controlled trials. Even then the important point is to establish the direction and magnitude of the causal relation, not the theory. Many theories can often fit the same data.”

Fitz-Gibbon, C. T. (2002). Researching outcomes of educational interventions. BMJ, 324(7346), 1155.