Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: The Rationalists of the 1950s (and before) also called themselves “Rationalists”, published by Owain Evans on November 28, 2021 on LessWrong.

TLDR

There’s an organization based in London called the Rationalist Association. It was founded in 1885. Historically, it focused on publishing books and articles related to atheism and science, including works by Darwin, Bertrand Russell, J. B. S. Haldane, George Bernard Shaw, H. G. Wells, and Karl Popper.

The topics covered overlap with the present-day rationalist movement (centered on Lesswrong). They include religion and atheism, philosophy (especially philosophy of science and ethics), evolution, and psychology.

According to Wikipedia, membership of the Rationalist Association peaked in 1959 with more than 5000 members and with Bertrand Russell as President.

This post displays some covers of Rationalist Association publications, and links to full-text articles and other resources.

Prior to reading this biography, I hadn't heard of these earlier rationalists. So I did some quick and shallow research. I’d be curious to know more about this history. It might be worth adding a note to this LW Wiki entry.

Past covers of the Rationalist Association publications

1896 Cover

This is a journal for short articles called the “Agnostic Annual” (later “Rationalist Annual”). The full text is here.

Some quotes from the article “Mind as controlled by matter” below.

1938 Cover

Includes articles by Bertrand Russell and evolutionary biologist and proto-transhumanist J. B. S. Haldane.

1954 Cover

1971 Cover

This is for a magazine called The Humanist, published by the Rationalist Association. It has since published articles by Richard Dawkins and Daniel Dennett.

Contents: “Rationalist Tasks”, “Motoring Safety”, “Quasi-rational Quarrelling” and the first appearance of the famous Philip Larkin poem that begins “They fuck you up, your mum and dad”.

Links and Full-text

1. Full-text articles from the Rationalist Annual by the prolific biologist, popular science writer and communist, J. B. S. Haldane. Some titles:

Why I am a Materialist

The Laws of Nature [probabilistic theories in physics and genetics, Laplace’s Demon]

The Limitations of Rationalism [cognitive limitations and biases -- see below]

A Rationalist Approach to the Problem of Sexual Relations

On Being Finite [reflections on death and meaning in life -- see below]

2. Full-text article by Ernest Gellner “On Being Wrong” [epistemic corrigibility]

3. Wikipedia on the (British) Rationalist Association, the Indian Rationalist Association, and the Rationalist International.

4. Archive of the Rationalist Annual and New Humanist (pay-walled).

Some Random Quotes

Yet it seemed to me that we have greater control over the material than the immaterial; it being easier, for instance, to regulate diet than to command success [see Scott Alexander]; and that, this being so, we must learn to call nothing common nor unclean, but consider a careful investigation into the influences of food, medicine, and climate as beneath the notice neither of philosopher nor moralist.‘Of all the great branches of human knowledge, medicine is that in which the accomplished results are most obviously imperfect and provisional. The medicine of inhalation is still in its infancy; and yet it is by inhalation that nature produces most of her diseases, and effects most of her cures’

From “Mind as controlled by matter” by Constance Plumptre (1896)

More serious is my own and other people’s limited reason­ing power. I simply cannot grasp a sufficiently complicated argument. The limitations of different intellects vary. Every educated person can factorize 35 in his or her head. I can factorize such numbers as 11,009; a few people can factorize six-figure numbers, however large their factors, Nobody can factorize twenty-figure numbers w...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: The Rationalists of the 1950s (and before) also called themselves “Rationalists”, published by Owain Evans on November 28, 2021 on LessWrong.

TLDR

There’s an organization based in London called the Rationalist Association. It was founded in 1885. Historically, it focused on publishing books and articles related to atheism and science, including works by Darwin, Bertrand Russell, J. B. S. Haldane, George Bernard Shaw, H. G. Wells, and Karl Popper.

The topics covered overlap with the present-day rationalist movement (centered on Lesswrong). They include religion and atheism, philosophy (especially philosophy of science and ethics), evolution, and psychology.

According to Wikipedia, membership of the Rationalist Association peaked in 1959 with more than 5000 members and with Bertrand Russell as President.

This post displays some covers of Rationalist Association publications, and links to full-text articles and other resources.

Prior to reading this biography, I hadn't heard of these earlier rationalists. So I did some quick and shallow research. I’d be curious to know more about this history. It might be worth adding a note to this LW Wiki entry.

Past covers of the Rationalist Association publications

1896 Cover

This is a journal for short articles called the “Agnostic Annual” (later “Rationalist Annual”). The full text is here.

Some quotes from the article “Mind as controlled by matter” below.

1938 Cover

Includes articles by Bertrand Russell and evolutionary biologist and proto-transhumanist J. B. S. Haldane.

1954 Cover

1971 Cover

This is for a magazine called The Humanist, published by the Rationalist Association. It has since published articles by Richard Dawkins and Daniel Dennett.

Contents: “Rationalist Tasks”, “Motoring Safety”, “Quasi-rational Quarrelling” and the first appearance of the famous Philip Larkin poem that begins “They fuck you up, your mum and dad”.

Links and Full-text

1. Full-text articles from the Rationalist Annual by the prolific biologist, popular science writer and communist, J. B. S. Haldane. Some titles:

Why I am a Materialist

The Laws of Nature [probabilistic theories in physics and genetics, Laplace’s Demon]

The Limitations of Rationalism [cognitive limitations and biases -- see below]

A Rationalist Approach to the Problem of Sexual Relations

On Being Finite [reflections on death and meaning in life -- see below]

2. Full-text article by Ernest Gellner “On Being Wrong” [epistemic corrigibility]

3. Wikipedia on the (British) Rationalist Association, the Indian Rationalist Association, and the Rationalist International.

4. Archive of the Rationalist Annual and New Humanist (pay-walled).

Some Random Quotes

Yet it seemed to me that we have greater control over the material than the immaterial; it being easier, for instance, to regulate diet than to command success [see Scott Alexander]; and that, this being so, we must learn to call nothing common nor unclean, but consider a careful investigation into the influences of food, medicine, and climate as beneath the notice neither of philosopher nor moralist.‘Of all the great branches of human knowledge, medicine is that in which the accomplished results are most obviously imperfect and provisional. The medicine of inhalation is still in its infancy; and yet it is by inhalation that nature produces most of her diseases, and effects most of her cures’

From “Mind as controlled by matter” by Constance Plumptre (1896)

More serious is my own and other people’s limited reason­ing power. I simply cannot grasp a sufficiently complicated argument. The limitations of different intellects vary. Every educated person can factorize 35 in his or her head. I can factorize such numbers as 11,009; a few people can factorize six-figure numbers, however large their factors, Nobody can factorize twenty-figure numbers w...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: [Linkpost] Being Normal by Brian Caplan, published by Gunnar Zarncke on November 27, 2021 on LessWrong.

Being Normal

The Principle of Normality: A normal person says what others say, but does what others do.

I found this via a Tweet by Paul Graham:

Very interesting point: Conformists conform separately in words and actions, and since conventional words are at odds with conventional actions, this thereby makes them hypocrites as well.

Thanks for listening. To help us out with The Nonlinear Library or to learn more, please visit nonlinear.org.

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: [Linkpost] Being Normal by Brian Caplan, published by Gunnar Zarncke on November 27, 2021 on LessWrong.

Being Normal

The Principle of Normality: A normal person says what others say, but does what others do.

I found this via a Tweet by Paul Graham:

Very interesting point: Conformists conform separately in words and actions, and since conventional words are at odds with conventional actions, this thereby makes them hypocrites as well.

Thanks for listening. To help us out with The Nonlinear Library or to learn more, please visit nonlinear.org.

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: The bonds of family and community: Poverty and cruelty among Russian peasants in the late 19th century, published by jasoncrawford on November 28, 2021 on LessWrong.

Village Life in Late Tsarist Russia is an ethnographic account of Russian peasants around 1900. The author, Olga Semyonova Tian-Shanskaia (“Semyonova” for short), spent four years researching in the villages—one of the first to study a people through prolonged direct observation and contact with them.

I was interested in the subject as part of learning, concretely, about the quality of life for people in various places and times and at various stages of development. Although material progress was advancing rapidly at the end of the 19th century, much of that progress had not yet reached the province of Riazan where Semyonova did most of her studies. What was life like there?

In brief, I went in expecting poverty, which I found. I did not expect to also find a disturbing degree of cruelty and abuse.

First, let me share some passages from the book that I highlighted, roughly organized by theme. At the end I’ll discuss how to interpret this and what to make of it.

In the block quotes that follow, brackets indicate insertions by the editor of the volume, David Ransel, not by me. Photographs are all taken from the Kindle edition (and presumed to be out of copyright).

Poverty

Here is the typical peasant diet:

Dinner consists of cabbage soup, porridge (kasha), or, again, potatoes and bread. The soup, of course, has no meat in it, just cabbage, but occasionally sour cream is added. Potatoes are mixed with kvass and onions. The porridge—usually millet—is eaten either with milk, in what is known as the thin form (kulesh), or in a thicker form made with hemp-seed oil. After dinner, the peasants take a rest and then return to the fields. They take along some bread for an afternoon snack sometime between three and five o’clock. When the sun sets, the peasants go home, and at about nine in the evening they eat their supper, which is warmed-over dinner, with the possible addition of skim milk.

You get a better sense of the standard of living from the foods that they consider special treats:

Foods that can be found on a peasant’s table only during the annual festival, or during a wedding or baptismal dinner, include pancakes (bliny), meat (veal designated for holidays—uboina), potato fritters (drachena), buns (pyshki), salamata (a kind of thin gruel), kalinnik (a kind of cake), fritters (olad’i), and cabbage soup with corned beef (solonina).

That, of course, is during good times. In bad times:

During a famine, peasant meals consist of stale bread moistened in water and mixed with goosefoot. The men make extra efforts to find any type of work, and sometimes the entire family goes out to beg. As soon as the snow melts, hungry children pick roots and herbs to eat, such as sorrel and clover. Peasants also make soup with goutweed (Aegopodium podagraria).

Another hallmark of poverty is the burning of solid fuels inside the home. Here’s a visualization of the problems that causes:

Stoves with chimneys are called “white,” while chimneyless stoves are referred to as “black.” When a “black” stove is being lighted, the door from the main room into the entryway is left open so that the smoke up to the level of the door is drawn out, but above that level it forms a blue and white blanket through which nothing can be seen. The top of the door is no higher than a rather short person, so that one has to stoop to enter the house (the ceiling itself is only 5’10” high). A good-sized man finds it difficult to stand up when the stove is being fired, because his eyes will be in the caustic cloud of smoke. Even when seated on a bench, one feels the acrid smoke in the eyes.

It’s bad enough to burn wood and coal; these peasants often had to bu...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: The bonds of family and community: Poverty and cruelty among Russian peasants in the late 19th century, published by jasoncrawford on November 28, 2021 on LessWrong.

Village Life in Late Tsarist Russia is an ethnographic account of Russian peasants around 1900. The author, Olga Semyonova Tian-Shanskaia (“Semyonova” for short), spent four years researching in the villages—one of the first to study a people through prolonged direct observation and contact with them.

I was interested in the subject as part of learning, concretely, about the quality of life for people in various places and times and at various stages of development. Although material progress was advancing rapidly at the end of the 19th century, much of that progress had not yet reached the province of Riazan where Semyonova did most of her studies. What was life like there?

In brief, I went in expecting poverty, which I found. I did not expect to also find a disturbing degree of cruelty and abuse.

First, let me share some passages from the book that I highlighted, roughly organized by theme. At the end I’ll discuss how to interpret this and what to make of it.

In the block quotes that follow, brackets indicate insertions by the editor of the volume, David Ransel, not by me. Photographs are all taken from the Kindle edition (and presumed to be out of copyright).

Poverty

Here is the typical peasant diet:

Dinner consists of cabbage soup, porridge (kasha), or, again, potatoes and bread. The soup, of course, has no meat in it, just cabbage, but occasionally sour cream is added. Potatoes are mixed with kvass and onions. The porridge—usually millet—is eaten either with milk, in what is known as the thin form (kulesh), or in a thicker form made with hemp-seed oil. After dinner, the peasants take a rest and then return to the fields. They take along some bread for an afternoon snack sometime between three and five o’clock. When the sun sets, the peasants go home, and at about nine in the evening they eat their supper, which is warmed-over dinner, with the possible addition of skim milk.

You get a better sense of the standard of living from the foods that they consider special treats:

Foods that can be found on a peasant’s table only during the annual festival, or during a wedding or baptismal dinner, include pancakes (bliny), meat (veal designated for holidays—uboina), potato fritters (drachena), buns (pyshki), salamata (a kind of thin gruel), kalinnik (a kind of cake), fritters (olad’i), and cabbage soup with corned beef (solonina).

That, of course, is during good times. In bad times:

During a famine, peasant meals consist of stale bread moistened in water and mixed with goosefoot. The men make extra efforts to find any type of work, and sometimes the entire family goes out to beg. As soon as the snow melts, hungry children pick roots and herbs to eat, such as sorrel and clover. Peasants also make soup with goutweed (Aegopodium podagraria).

Another hallmark of poverty is the burning of solid fuels inside the home. Here’s a visualization of the problems that causes:

Stoves with chimneys are called “white,” while chimneyless stoves are referred to as “black.” When a “black” stove is being lighted, the door from the main room into the entryway is left open so that the smoke up to the level of the door is drawn out, but above that level it forms a blue and white blanket through which nothing can be seen. The top of the door is no higher than a rather short person, so that one has to stoop to enter the house (the ceiling itself is only 5’10” high). A good-sized man finds it difficult to stand up when the stove is being fired, because his eyes will be in the caustic cloud of smoke. Even when seated on a bench, one feels the acrid smoke in the eyes.

It’s bad enough to burn wood and coal; these peasants often had to bu...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Wikipedia editing is important, tractable, and neglected, published by Darius M on November 28, 2021 on The Effective Altruism Forum.

1. Key Takeaways

The case for Wikipedia editing in a nutshell: Wikipedia articles are widely read and trusted, there is much low hanging fruit for improvement, and editing Wikipedia has low barriers to entry and is relatively low effort. Consequently, improving a Wikipedia article may benefit the reasoning and actions of its thousands, and often millions, of readers. Moreover, since Wikipedia is a global public good, improvements to Wikipedia are likely undersupplied relative to the socially optimal level.

Careful prioritisation is crucial. Improving or creating some Wikipedia articles could easily be 100x to 1,000x as valuable as others. The key factors to consider for prioritisation are (i) pageviews, (ii) audience, (iii) topic, (iv) room for improvement, and (v) language.

Respecting Wikipedia community rules and norms is key. The Wikipedia community is wary of people making edits to promote a particular idea, person, or organisation, especially when there are relevant conflicts of interest. Consequently, edits that violate Wikipedia rules and norms may be actively harmful and are likely to be deleted. However, there are currently still very many genuine gaps in the quality and coverage of Wikipedia articles, and filling these gaps tends to work well and is regarded highly.

Contributing to or starting a WikiProject on an important topic may be valuable. A WikiProject is a group of contributors who want to work together as a team to improve Wikipedia. A WikiProject allows for more efficient collaboration, by providing a centralised place where interested editors can make plans and discuss proposals.

There are self-interested reasons to edit Wikipedia. In particular, Wikipedia editing can be really fun, it is a great opportunity to learn more about a topic, it may help you improve your writing, and it may be a useful signal in some communities or for some professional opportunities.

Some EA-relevant content is better suited to a specialised EA Wiki than to Wikipedia. For instance, content that is too niche to meet Wikipedia’s notability requirements.

Please note that much of this post is not original, drawing on existing writing (see the “Relevant Resources” section). However, I felt it was important to add to, synthesise and popularise these ideas here on the forum. Any mistakes are my own.

2. Respecting Wikipedia Rules

Before giving the positive argument for Wikipedia editing, I want to stress the importance of becoming familiar with and respecting the rules and norms governing Wikipedia editing.

Lack of familiarity with the relevant rules and norms is one of the main reasons editors have their contributions reverted. The most important ones include:

Neutral point of view: “All Wikipedia articles (...) must be written from a neutral point of view, representing significant views fairly, proportionately and without bias.”

Verifiability: “Material challenged or likely to be challenged, and all quotations, must be attributed to a reliable, published source.”

No original research: “Wikipedia does not publish original thought (...) Articles may not contain any new analysis or synthesis of published material that serves to advance a position not clearly advanced by the sources.”

Notability: “Article and list topics must be notable, or “worthy of notice”. (...) if no reliable, independent sources can be found on a topic, then it should not have a separate article.”

Conflict of interest (COI): “COI editing involves contributing to Wikipedia about yourself, family, friends, clients, employers, or your financial and other relationships. (...) COI editing is strongly discouraged on Wikipedia.”

Paid-contribution disclosure: “If you are paid in an...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Wikipedia editing is important, tractable, and neglected, published by Darius M on November 28, 2021 on The Effective Altruism Forum.

1. Key Takeaways

The case for Wikipedia editing in a nutshell: Wikipedia articles are widely read and trusted, there is much low hanging fruit for improvement, and editing Wikipedia has low barriers to entry and is relatively low effort. Consequently, improving a Wikipedia article may benefit the reasoning and actions of its thousands, and often millions, of readers. Moreover, since Wikipedia is a global public good, improvements to Wikipedia are likely undersupplied relative to the socially optimal level.

Careful prioritisation is crucial. Improving or creating some Wikipedia articles could easily be 100x to 1,000x as valuable as others. The key factors to consider for prioritisation are (i) pageviews, (ii) audience, (iii) topic, (iv) room for improvement, and (v) language.

Respecting Wikipedia community rules and norms is key. The Wikipedia community is wary of people making edits to promote a particular idea, person, or organisation, especially when there are relevant conflicts of interest. Consequently, edits that violate Wikipedia rules and norms may be actively harmful and are likely to be deleted. However, there are currently still very many genuine gaps in the quality and coverage of Wikipedia articles, and filling these gaps tends to work well and is regarded highly.

Contributing to or starting a WikiProject on an important topic may be valuable. A WikiProject is a group of contributors who want to work together as a team to improve Wikipedia. A WikiProject allows for more efficient collaboration, by providing a centralised place where interested editors can make plans and discuss proposals.

There are self-interested reasons to edit Wikipedia. In particular, Wikipedia editing can be really fun, it is a great opportunity to learn more about a topic, it may help you improve your writing, and it may be a useful signal in some communities or for some professional opportunities.

Some EA-relevant content is better suited to a specialised EA Wiki than to Wikipedia. For instance, content that is too niche to meet Wikipedia’s notability requirements.

Please note that much of this post is not original, drawing on existing writing (see the “Relevant Resources” section). However, I felt it was important to add to, synthesise and popularise these ideas here on the forum. Any mistakes are my own.

2. Respecting Wikipedia Rules

Before giving the positive argument for Wikipedia editing, I want to stress the importance of becoming familiar with and respecting the rules and norms governing Wikipedia editing.

Lack of familiarity with the relevant rules and norms is one of the main reasons editors have their contributions reverted. The most important ones include:

Neutral point of view: “All Wikipedia articles (...) must be written from a neutral point of view, representing significant views fairly, proportionately and without bias.”

Verifiability: “Material challenged or likely to be challenged, and all quotations, must be attributed to a reliable, published source.”

No original research: “Wikipedia does not publish original thought (...) Articles may not contain any new analysis or synthesis of published material that serves to advance a position not clearly advanced by the sources.”

Notability: “Article and list topics must be notable, or “worthy of notice”. (...) if no reliable, independent sources can be found on a topic, then it should not have a separate article.”

Conflict of interest (COI): “COI editing involves contributing to Wikipedia about yourself, family, friends, clients, employers, or your financial and other relationships. (...) COI editing is strongly discouraged on Wikipedia.”

Paid-contribution disclosure: “If you are paid in an...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Why Study Physics?, published by johnswentworth on November 27, 2021 on LessWrong.

Physics seems to have a bunch of useful epistemic techniques which haven’t been made very legible yet.

The two big legible epistemic techniques in technical fields are Mathematical Proofs, and The Scientific Method. Either derive logically X from some widely-accepted axioms, or hypothesize X and then do a bunch of experiments which we’d expect to come out some other way if X were false. It seems pretty obvious that science requires a bunch of pieces besides those in order to actually work in practice, but those are the two which we’ve nailed down most thoroughly.

Then there’s less-legible methods. Things like fermi estimates, gears-level models, informal mathematical arguments, an aesthetic sense for kinds-of-models-which-tend-to-generalize-well, the habit of figuring out qualitative features of an answer before calculating it, back-of-the-envelope approximations, etc.

Take informal mathematical arguments, for example. We’re talking about things like the use of infinitesimals in early calculus, or delta functions, or Fourier methods, or renormalization. Physicists used each of these for decades or even centuries before their methods were rigorously proven correct. In each case, one could construct pathological examples in which the tool broke down, yet physicists in practice had a good sense for what kinds-of-things one could and could not do with the tools, based on rough informal arguments. And they worked! In every case, mathematicians eventually came along and set the tools on rigorous foundations, and the tools turned out to work in basically the cases a physicist would expect.

So there’s clearly some epistemic techniques here which aren’t captured by Mathematical Proof + The Scientific Method. Physicists were able to figure out correct techniques before the proofs were available. The Scientific Method played a role - physicists could check their results against real-world data - but that’s mostly just checking the answer. The hard part was to figure out which answer to check in the first place, and that involved informal mathematical arguments.

We don’t really have a legible Art of Informal Mathematical Arguments, the way we have a legible Art of Mathematical Proofs or Art of Scientific Method. Informal mathematics clearly played a key role historically in figuring out useful tools, and will likely continue to play a key role in the future, but we don’t have a step-by-step checklist to follow in order to use informal mathematical arguments (the way we do for The Scientific Method), or even a checklist to verify that we’ve applied informal mathematical arguments correctly (the way we can for Mathematical Proofs). If someone says that my informal mathematical argument is wrong, and I can’t either convert it to a formal proof or show some definitive experiment, then I don’t have a clear standard way to argue that it’s correct.

Yet there’s clearly something making informal mathematical arguments correlate quite highly with truth (if imperfectly), because they work well in practice!

The same applies to Fermi estimates. They work remarkably well in practice, yet there’s not a standard step-by-step checklist. There’s not some standard rules to check whether a Fermi estimate is correct. If someone disagrees with my Fermi estimate, there’s not a way for me to establish correctness other than putting in all the work to find more-rigorously-estimated numbers.

The same applies to gears-level models. Plenty of physicists (and engineers, and others in technical fields) have an intuitive sense that a gears-level model is useful and powerful in ways that a black-box model isn’t. But if someone comes along and says that their 50-variable linear regression gives more precise predictions than a mod...

Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Why Study Physics?, published by johnswentworth on November 27, 2021 on LessWrong.

Physics seems to have a bunch of useful epistemic techniques which haven’t been made very legible yet.

The two big legible epistemic techniques in technical fields are Mathematical Proofs, and The Scientific Method. Either derive logically X from some widely-accepted axioms, or hypothesize X and then do a bunch of experiments which we’d expect to come out some other way if X were false. It seems pretty obvious that science requires a bunch of pieces besides those in order to actually work in practice, but those are the two which we’ve nailed down most thoroughly.

Then there’s less-legible methods. Things like fermi estimates, gears-level models, informal mathematical arguments, an aesthetic sense for kinds-of-models-which-tend-to-generalize-well, the habit of figuring out qualitative features of an answer before calculating it, back-of-the-envelope approximations, etc.

Take informal mathematical arguments, for example. We’re talking about things like the use of infinitesimals in early calculus, or delta functions, or Fourier methods, or renormalization. Physicists used each of these for decades or even centuries before their methods were rigorously proven correct. In each case, one could construct pathological examples in which the tool broke down, yet physicists in practice had a good sense for what kinds-of-things one could and could not do with the tools, based on rough informal arguments. And they worked! In every case, mathematicians eventually came along and set the tools on rigorous foundations, and the tools turned out to work in basically the cases a physicist would expect.

So there’s clearly some epistemic techniques here which aren’t captured by Mathematical Proof + The Scientific Method. Physicists were able to figure out correct techniques before the proofs were available. The Scientific Method played a role - physicists could check their results against real-world data - but that’s mostly just checking the answer. The hard part was to figure out which answer to check in the first place, and that involved informal mathematical arguments.

We don’t really have a legible Art of Informal Mathematical Arguments, the way we have a legible Art of Mathematical Proofs or Art of Scientific Method. Informal mathematics clearly played a key role historically in figuring out useful tools, and will likely continue to play a key role in the future, but we don’t have a step-by-step checklist to follow in order to use informal mathematical arguments (the way we do for The Scientific Method), or even a checklist to verify that we’ve applied informal mathematical arguments correctly (the way we can for Mathematical Proofs). If someone says that my informal mathematical argument is wrong, and I can’t either convert it to a formal proof or show some definitive experiment, then I don’t have a clear standard way to argue that it’s correct.

Yet there’s clearly something making informal mathematical arguments correlate quite highly with truth (if imperfectly), because they work well in practice!

The same applies to Fermi estimates. They work remarkably well in practice, yet there’s not a standard step-by-step checklist. There’s not some standard rules to check whether a Fermi estimate is correct. If someone disagrees with my Fermi estimate, there’s not a way for me to establish correctness other than putting in all the work to find more-rigorously-estimated numbers.

The same applies to gears-level models. Plenty of physicists (and engineers, and others in technical fields) have an intuitive sense that a gears-level model is useful and powerful in ways that a black-box model isn’t. But if someone comes along and says that their 50-variable linear regression gives more precise predictions than a mod...