Misquotes by David Deutsch

I’ve discovered that David Deutsch (DD) is an unreliable quoter. His book The Beginning of Infinity (BoI) contains many serious quotation errors, and he has misquoted elsewhere too.

For context, DD and I were close associates for a decade. I helped with BoI for 7 years and wrote over 200 pages of comments, suggestions and edits on drafts of the book. I learned a lot from him but I trusted his scholarship too much. I promoted his books. I was wrong about him and his books in multiple ways. My mistake. I retract my previous endorsements and recommendations of DD’s books. That doesn’t mean the books are awful or shouldn’t be read, but I no longer want to promote them myself. There are good ideas mixed in, but be wary of major problems.

Misquotes in The Beginning of Infinity

Block quotes are from BoI unless otherwise stated.

I think there will certainly not be novelty, say for a thousand years. This thing cannot keep going on so that we are always going to discover more and more new laws. If we do, it will become boring that there are so many levels one underneath the other . . . We are very lucky to live in an age in which we are still making discoveries. It is like the discovery of America – you only discover it once.
The Character of Physical Law (1965)

That’s different than what Feynman wrote. DD changed the words “perpetual novelty” to “novelty”. DD also changed “keep on going” to “keep going on”. (More details.)

Behind it all is surely an idea so simple, so beautiful, that when we grasp it – in a decade, a century, or a millennium – we will all say to each other, how could it have been otherwise?
John Archibald Wheeler, Annals of the New York Academy of Sciences, 480 (1986)

What Wheeler actually wrote was "Behind it all is surely an idea so simple, so beautiful, so compelling that when–in a decade, a century, or a millennium–we grasp it, we will all say to each other, how could it have been otherwise?”. DD deleted “so compelling” and moved “we grasp it” to before the dashed part. (More details.)

As the physicist Richard Feynman said, ‘Science is what we have learned about how to keep from fooling ourselves.’

Feynman didn’t say that. It’s not even a documented quote with some changes. It seems made up with no original source or evidence.

I checked the web and some Feynman books and speeches. It’s likely that the misquote started in 2000 in the article Magical Thinking (my thanks to Justin Mallone for finding that article), which paraphrased Feynman that way without using quote marks or giving a source. Unfortunately, the wording made it sound like it was an actual quote, so I think people started spreading it as a quote. Then DD probably got the misquote from an unreliable webpage and put it in his book without trying to find a primary source or telling his readers which unreliable secondary source he used. There are now two books which give this quote and cite it to as quoted in BoI. There’s also a book which gives the quote with a footnote saying that the author was unable to find a source for the quote (then don’t put it in your book!).

Feynman said some similar ideas in Cargo Cult Science, but the wordings are different. DD didn’t take the quote from there and add one or two errors (like he did with some other quotes, where you can tell that he’s quoting a specific thing incorrectly). It’s too different to have come from that speech.

Popper wrote:

The inductivist or Lamarckian approach operates with the idea of instruction from without, or from the environment. But the critical or Darwinian approach only allows instruction from within – from within the structure itself . . .

I contend that there is no such thing as instruction from without the structure. We do not discover new facts or new effects by copying them, or by inferring them inductively from observation, or by any other method of instruction by the environment. We use, rather, the method of trial and the elimination of error. As Ernst Gombrich says, ‘making comes before matching’: the active production of a new trial structure comes before its exposure to eliminating tests.
The Myth of the Framework

DD ends the first sentence of the second paragraph with “without the structure” and then a period. Instead of a period, Popper had a comma there and continued the sentence. Then, the rest of that paragraph that DD quotes is actually from a different section of the book. DD combined sentences from different places in the book and presented them as one paragraph with no ellipsis or square brackets to indicate a modification.

And DD left out the words “In fact,” before “I contend”. DD also put an ellipsis at the end of the first paragraph when that should be a period. There are no omitted words there. The paragraph ends there and DD continues without skipping a paragraph. DD also left out Popper’s italics.

A similar misquote also appeared on the Taking Children Seriously (TCS) website (mirror). DD co-founded TCS with Sarah Fitz-Claridge and she’s my best guess at the author of that misquote, though it could have been DD. Either way, he has responsibility for what it says on the official website of the movement he co-founded (particularly for pages, like this one, with no author specified).

Judging by the similarities, the misquote in BoI was likely based on the TCS website misquote. Even when a secondary source is accurate, it’s problematic to take a secondary source quote and then edit it without checking the original. When you do that, you’re making edits without knowing the original context and wording, so you aren’t in a good enough position to judge what edits are OK.

(More details about the TCS website version of the misquote.)

Thanks to Dec for telling me that this misquote is also in BoI after I wrote about the version from the TCS website.

As the physicist Stephen Hawking put it, humans are ‘just a chemical scum on the surface of a typical planet that’s in orbit round a typical star on the outskirts of a typical galaxy’.

This quote seems to be made up based on a similar Hawking quote about “chemical scum” from the 1995 TV program (Reality on the Rocks: Beyond Our Ken by Ken Campbell (IMBD, trailer)). Interestingly, DD had quoted it correctly in The Fabric of Reality as “The human race is just a chemical scum on a moderate-sized planet, orbiting round a very average star in the outer suburb of one among a hundred billion galaxies.” I didn’t find the original video, but it’s quoted that way in various places online that aren’t based on DD’s writing. (Some sources have “around” instead of “round”, which is an understandable difference given how similar those words can sound when spoken out loud.)

It seems that DD made up this misquote for his 2005 TED talk and then based the quote in BoI on his talk. Alan Forrester checked the books The large scale structure of space-time, A Brief History of Time, The Grand Design, The Nature of Space and Time and The Universe in a Nutshell, but found that none contain the word “scum”. And I can’t find any online sources for Hawking ever saying the BoI version of the quote (whereas with the The Fabric of Reality version, I easily found other online sources).

This misquote doesn’t seem fully accidental. DD changed the quote to be more elegant and catchy by repeating “typical” three times. I’ve noticed that many of DD’s misquotes involve changing text to sound nicer.

(More details.)

[Horgan believed] that science has the ability to ‘resolve questions’ objectively […]

Horgan actually wrote “Scientists have the ability to pose questions and resolve them in a way that critics, philosophers, historians cannot.” DD changed Horgan’s words “resolve them” to “resolve questions”, which is wrong without using square brackets to indicate an edit. (More details.)

The issue of what exactly needs to be explained in an ‘appearance of design’ was first addressed by the clergyman William Paley, the finest exponent of the argument from design. In 1802, before Darwin was born, he published the following thought experiment in his book Natural Theology.

It’s unclear what, if anything, “appearance of design” is a quote from, but it’d be understandable if a reader believed it was a quote of Paley in Natural Theology. But it’s not in that book.

[Paley wrote:]

The inference we think is inevitable, that the watch must have had a maker . . . There cannot be design without a designer; contrivance without a contriver; order without choice; arrangement without anything capable of arranging; subserviency and relation to a purpose without that which could intend a purpose; means suitable to an end . . . without the end ever having been contemplated or the means accommodated to it. Arrangement, disposition of parts, subserviency of means to an end, relation of instruments to a use imply the presence of intelligence and mind.

DD changed the words “any thing” to the word “anything” and changed “an use” to “a use”. DD also quoted from both chapters 1 and 2, but presented it as single paragraph with ellipses. DD also removed a comma near the end before “imply the presence of intelligence and mind” which helped the reader understand the text. (DD edited other punctuation too, but this punctuation edit stood out to me because it’s significantly worse than the original.) (More details.)

As Hawking once put it, ‘Television sets could come out [of a naked singularity].’

Thanks to Alan Forrester for looking into this quote at my request. He was unable to find Hawking saying this. He searched the web and the following books: The large scale structure of space-time, A Brief History of Time, The Grand Design, The Nature of Space and Time and The Universe in a Nutshell.

As Hofstadter remarked, ‘In retrospect, I am quite amazed at how much genuine intelligence I was willing to accept as somehow having been implanted in the program . . . It is clear that I was willing to accept a huge amount of fluidity as achievable in this day and age simply by putting together a large bag of isolated tricks, kludges and hacks.’

Hofstadter’s actual paragraph ends with “a large bag of isolated tricks-kludges and hacks, as they say.” DD’s punctation edits changed the meaning. Hofstadter said “isolated tricks” and then gave “kludges and hacks” as a rewording of “isolated tricks”. DD changed it to a list of three things, “tricks, kludges and hacks” and made it sound like the modifier “isolated” applies to all three, whereas in the original it applied only to “tricks”. As a list, it means that all three things were put together. In the original, it says they put together tricks, and then provides the additional information that the tricks could be characterized as kludges and hacks as people (informally) say.

Thanks to Dec for bringing up this misquote.

Representative Roger Q. Mills of Texas complained in 1882, ‘I thought . . . that mathematics was a divine science. I thought that mathematics was the only science that spoke to inspiration and was infallible in its utterances [but] here is a new system of mathematics that demonstrates the truth to be false.’

This text is available in the Congressional Record. DD changed the words "by inspiration" to "to inspiration". It’s also misleading that where DD wrote “[but]”, with no ellipsis, he skipped multiple sentences and continued with text from a different paragraph.

DD likely copied this misquote from Fair Representation without telling his readers that he was trusting a secondary source without fact checking it, and without letting readers know which secondary source he was using.

Thanks to Justin Mallone for looking this up at my request.

Before Blackmore and others realized the significance of memes in human evolution, all sorts of root causes had been suggested [...] [T]here is the ‘Machiavellian hypothesis’ that human intelligence evolved in order to predict the behaviour of others, and to fool them. […] Blackmore’s ‘meme machine’ idea, that human brains evolved in order to replicate memes, must be true.

At first I read “Machiavellian hypothesis” as a quote of Blackmore from her book The Meme Machine that DD mentioned earlier and included in his bibliography. If so, it's a misquote. That phrase isn’t in her book.

But maybe “Machiavellian hypothesis” is merely meant to be the name of a hypothesis. If so, it’s the wrong name. The correct name is "Machiavellian Intelligence”, as one can find out from Blackmore’s book or Wikipedia. Blackmore has an index entry for “Machiavellian Intelligence” and cites two books with “Machiavellian Intelligence” in their title. She also writes “An influential version of social theory is the ‘Machiavellian Intelligence’ hypothesis (Byrne and Whiten 1988; Whiten and Byrne 1997).”. It appears that DD read her book, misremembered the name of the hypothesis, didn’t check it, and put quote marks around it. (More details.)

The more important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote . . . Our future discoveries must be looked for in the sixth place of decimals.
Albert Michelson, address at the opening of the Ryerson Physical Laboratory, University of Chicago, 1894

The source for this, which DD didn’t specify, is the book Light Waves and Their Uses (1903) by Albert Michelson. The speaker wrote down what he said in his own book. Michelson wrote:

Many other instances might be cited, but these will suffice to justify the statement that "our future discoveries must be looked for in the sixth place of decimals."

DD incorrectly quoted this as Michelson saying “[o]ur future discoveries must be looked for in the sixth place of decimals” himself, when Michelson actually had it in quote marks and talked about that statement. Deleting quote marks within a quote is misquoting. (More details.)

For example, as I wrote in The Fabric of Reality:

Consider one particular copper atom at the tip of the nose of the statue of Sir Winston Churchill that stands in Parliament Square in London. Let me try to explain why that copper atom is there. It is because Churchill served as prime minister in the House of Commons nearby; and because his ideas and leadership contributed to the Allied victory in the Second World War; and because it is customary to honour such people by putting up statues of them; and because bronze, a traditional material for such statues, contains copper, and so on. Thus we explain a low-level physical observation – the presence of a copper atom at a particular location – through extremely high-level theories about emergent phenomena such as ideas, leadership, war and tradition.

There is no reason why there should exist, even in principle, any lower-level explanation of the presence of that copper atom than the one I have just given. Presumably a reductive ‘theory of everything’ would in principle make a low-level prediction of the probability that such a statue will exist, given the condition of (say) the solar system at some earlier date. It would also in principle describe how the statue probably got there. But such descriptions and predictions (wildly infeasible, of course) would explain nothing. They would merely describe the trajectory that each copper atom followed from the copper mine, through the smelter and the sculptor’s studio and so on . . . In fact such a prediction would have to refer to atoms all over the planet, engaged in the complex motion we call the Second World War, among other things. But even if you had the superhuman capacity to follow such lengthy predictions of the copper atom’s being there, you would still not be able to say ‘Ah yes, now I understand why they are there’. [You] would have to inquire into what it was about that configuration of atoms, and those trajectories, that gave them the propensity to deposit a copper atom at this location. Pursuing that inquiry would be a creative task, as discovering new explanations always is. You would have to discover that certain atomic configurations support emergent phenomena such as leadership and war, which are related to one another by high-level explanatory theories. Only when you knew those theories could you understand why that copper atom is where it is.

In addition to checking this using ebooks, I also compared hardback copies of both books. It’s FoR pp. 22-23 and BoI pp. 109-110.

DD quotes “understand why they are there” but the original reads “understand why it is there”. DD changed the words “it is” to “they are”.

DD quotes "Pursuing that inquiry”, but FoR says “this inquiry”. DD changed the word “this” to “that”.

DD quotes “understand why that copper atom is where it is”. DD omitted the word “fully”. The original said “understand fully why”.

DD wrote “[You]” in BoI, which is an incorrect use of square brackets. He skipped two sentences and should have used an ellipsis. And it says “You” in the original, so he shouldn’t put it in square brackets since it isn’t modified. Square brackets can only replace an ellipsis when the text in square brackets replaces/summarizes/paraphrases all the skipped text, but the word “You” doesn’t replace the skipped sentences.

The italics “why” and “what it was” are not italicized in FoR.

The ellipsis DD used in “studio and so on . . . In fact” is incorrect because the original had a period after “so on”. There should be four dots there (one for the period, and three for the ellipsis), not three dots.

DD doesn’t even quote himself accurately.

Other Misquotes

In The Fabric of Reality, DD wrote:

Mystery is part of the very concept of time that we grow up with. St Augustine, for example, said:

What then is time? If no one asks me, I know; if I wish to explain it to one who asks, I know not. (Confessions)

This quote has some word changes compared to the edition of Confessions that I checked. However, there are other English translations, so it could be an accurate quote of one of those. DD didn’t say which translation he used, which is more problematic than usual when quoting a particular translation rather than quoting something with a single, unambiguous wording that could be looked up.

DD wrote in Not Merely the Finest TV Documentary Series Ever Made:

As Karl Popper put it, we humans can “let our ideas die in our place.”

I found Popper saying something similar three times, but he didn’t use that wording. I think DD relies on his memory for this quote, instead of checking a source. He’s quoted it different ways in different places (e.g. with “theories” instead of “ideas” in Why It’s Good To Be Wrong and BoI). DD should get quotes from sources instead of putting quote marks around what he believes he remembers someone writing.

Popper said similar things in The Myth of the Framework (“By criticizing our theories we can let our theories die in our stead.”), In Search of a Better World (“Now we can let our theories die in our place.”), and Natural Selection and the Emergence of Mind (“Let our conjectures, our theories, die in our stead!”).

DD’s associate Chiara Marletto also misquoted Popper as saying "let our ideas die in our place.”.

DD’s associate Sarah Fitz-Claridge misquoted William Godwin and intentionally sanitized a quote about slavery. She gives “The condition of a … slave in the West-Indies, is in many respects preferable to that of the youthful son of a free-born European. The slave is purchased upon a view of mercantile speculation; and, when he has finished his daily portion of labour, his master concerns himself no further about him. But the watchful care of the parent is endless. The youth is never free from the danger of grating interference.”. She misquoted by changing the words "of its grating" to “of grating”. And she sanitized the 1797 quote by changing "negro-slave" into "... slave”. (I think that’s an incorrect use of an ellipsis, too.) Also, the quote is horrible because it downplays how bad slavery was, so it’s disturbing that Fitz-Claridge liked the quote enough to highlight it.

Fitz-Claridge also misquoted The Myth of the Framework. It’s some of the same Popper material misquoted in BoI and on the TCS website, but misquoted differently. This time, Fitz-Claridge changed “that” to “which” and got the page numbers wrong. (More details in the second update.)

Smaller Issues

DD frequently doesn’t give sources for quotes which makes it harder to check their accuracy. By leaving out sources, he’s asking his reader to trust him. But he made many quoting errors, so that trust would be misplaced.

DD repeatedly writes “X … Y” when X and Y are from different paragraphs or even different sections of a book. This is misleading. He also does it when X is a complete sentence, which makes it look like X is not a complete sentence.

DD frequently changes capitalization and punctuation without square brackets to indicate the change. DD capitalizes stuff to make it look like the start of a sentence when it isn’t (both at the start of a quote or after an ellipsis). DD also puts periods inside the quote marks after quoting a partial sentence, which makes it look like that was the end of the sentence when it wasn’t. DD also repeatedly puts a space then an ellipsis after a sentence ends, which should be a period then ellipsis but he changed the period to a space. So he makes stuff look like the start or end of a sentence when it isn’t, and then other times he makes stuff look like it’s not the end of a sentence when it is.

DD doesn’t appear to have a consistent policy for periods going inside or outside of quotes. E.g. I searched an electronic copy of BoI and found 188 instances of a single close quote followed by a period, and 88 instances of a period followed by a single close quote (and 3 instances of period, single close quote, and period again, which all involved a number, ellipsis, close quote, then period). DD often ends quotes with a period inside the quotation marks when the original sentence doesn’t end there, but other times he puts the period outside the quotation marks, and I don’t know why. DD is also inconsistent about italicizing quotes the same way they are in the original.

There are standard guidelines for how to do quotations, which DD violates, in addition to the larger misquote issues I presented above. For example, Working with Quotations, from Suny Empire State College, says:

Remember that when you do choose to use direct quotations, you need to retain the exact wording, spelling, capitalization, and punctuation of the original source.

DD went to both Oxford and Cambridge. I don’t think they teach lower standards than state colleges, and in any case he hasn’t followed their guidelines. For example, this Guide for authors and editors from the Oxford University Press says:

Quoted matter must reflect the original source exactly in spelling, punctuation, and capitalization. Please double-check all quotations against the sources from which you have taken them to ensure that you have copied accurately.

It must be possible for the reader to identify the work from which a quotation has been taken.

The University Of Oxford Style Guide says “Place any punctuation which does not belong to the quote outside the quotation marks (except closing punctuation if the end of the quote is also the end of the sentence).”

The Cambridge Editorial Style Guide says “A full stop is used outside the quotation mark if the quote is only part of a sentence.” and “Always source quotations”.

Taking Credit from Karl Popper

There’s another scholarship issue in DD’s books. I was horrified to discover that Karl Popper’s name is only in The Fabric of Reality (FoR) chapter 3 two times. That chapter is focused on sharing Popper’s ideas. But it doesn’t give adequate credit. In particular, the diagrams (3.1, 3.2, 3.3) are clearly based on Popper’s diagrams in Objective Knowledge, but DD never tells the reader that they’re modified from Popper. (More details.)

DD has presented himself as very humble and modest. He’s claimed multiple times to be only footnotes to Popper (which comes off as exaggerated modesty, rather than convincing his fans that it’s actually true). But DD has simultaneously misled readers to believe he accomplished much more than he did, e.g. in FoR ch. 3. This is a pattern. For example, in a 2016 paper, The logic of experimental tests, particularly of Everettian quantum theory, DD wrote:

An important consequence of this explanatory conception of science is that experimental results consistent with a theory T do not constitute support for T. That is because they are merely explicanda. A new explicandum may make a theory more problematic, but it can never solve existing problems involving a theory (except by making rival theories problematic – see Section 3). The asymmetry between refutation (tentative) and support (non-existent) in scientific methodology is better understood in this way, by regarding theories as explanations, than through Popper's (op. cit.) own argument from the logic of predictions, appealing to what has been called the ‘arrow of modus ponens’. Scientific theories are only approximately modelled as propositions, but they are precisely explanations.

This passage misleads readers into believing that DD improved on Popper by making a better argument focused on explanations instead of on the logic of predictions. Most readers would be surprised to discover that Popper made both arguments. Popper did make the logic of predictions argument (which is less important but was worth making too) but also made the other argument that DD is implying is his own original work. DD made some original contributions to epistemology, but not this one.

You can search Popper’s Conjectures and Refutations (C&R) for words like "tentative", "explanation", and "support" to see that DD is less original than he implies. Popper also covers these issues in other books. I’ll give one example from C&R:

For a scientific theory—an explanatory theory—is, if anything, an attempt to solve a scientific problem, that is to say, a problem concerned or connected with the discovery of an explanation.[6]

This clearly shows that Popper viewed scientific theories as explanatory theories. DD didn’t come up with the idea that scientific theories are explanations. The footnote at the end of that quote refers readers to more of Popper’s writing. Popper talked about explanation often. Popper also came up with the asymmetry between refutation (tentative) and support (non-existent). Popper emphasized refutation, said it was only tentative, and is also the person who challenged thousands of years of philosophical tradition by arguing that support is non-existent. Popper drew multiple major distinctions between negative and positive approaches to epistemology.

DD also gets other people to praise him while he presents himself as humble. For example, his TCS co-founder Sarah Fitz-Claridge (SFC) wrote that Popper invented a philosophy of science and that David Deutsch and his TCS philosophy had extended Popper’s epistemology to apply outside of science. (SFC probably wrote that. It’s on an official TCS page, but doesn’t specify the author, so it could have been written by DD.) That’s a major misrepresentation. Popper was seeking a general theory of knowledge, and said so, and applied it outside of science. (More details.)

DD has gotten his associates to praise him as e.g. having “the greatest mind ever”. SFC believes that DD made major improvements on Popper, and so do many of DD’s fans. I don’t believe it’s an accident that many people overestimate DD in ways similar to his co-founder who publicly promotes him. It looks like a strategy where DD plays humble while having other people say things that would sound arrogant coming from him. (More details.)

In 2012, SFC wrote to the official Fabric of Reality discussion group (archive of FoR posts) (my italics):

In my view it would be much more accurate to say that David has the greatest mind ever to have existed. His thinking is breathtakingly logical and brilliant. His ideas have changed the world and will do so even more profoundly in the future. I have never met anyone more pure, more truth-seeking and more open to criticism than David.

In 2000, SFC wrote to TCS list (my italics):

So really, people should not speak of Popper, but of Deutsch, because it was David who came up with the link between Popper's ideas and educational theory.

Note that DD has a history of secretly ghostwriting stuff which SFC then claims to be the author of. (Source: DD’s friend. He or she was friends with DD before DD turned 18 and they’re still friends now, over 50 years later. He or she had many discussions about TCS, Popper and more with DD and SFC. DD introduced me to the friend and I had some discussions with him or her.) Full disclosure: In the past, I’ve posted a few things that DD wrote, but under my own name, with his permission and approval. I did this when (as best I remember) I wanted to share something good that he told me, which I thought would benefit the world, but he didn’t want to share it himself and wouldn’t let me post it and attribute it to him or to an anonymous person, but he would let me post it under my name without attributing it to anyone. Here’s an example that I remember (I think it was the most significant, memorable instance). More often, I wrote stuff myself that was based on things DD told me, and he didn’t want credit but was happy for me to say it. At other times, DD helped edit my writing and a sentence or two of his ended up in the final version without credit (he didn’t want credit). DD had substantial influence over some of my early writing, and he also has had substantial influence over some of SFC’s writing that he didn’t fully ghostwrite.

Conclusion

I was mistaken about how good DD’s books are. They’re worse than I thought. I still think there is significant value in those books, but you can’t trust DD’s scholarship. Besides distrusting direct quotes given by DD, you should also distrust paraphrases or summaries of what other people said or thought. You have to check things yourself if you actually want to know. DD is too unreliable. And don’t use DD as a secondary source. Don’t spread quotes that DD quoted; quote directly from the original source or don’t use it. Some people are spreading his misquotes (they’ve even been repeated in books).

FYI, I don’t think DD is especially bad at quoting compared to others. Lots of books and academic articles have major errors related to quotes, paraphrases, cites or facts. But for a book to be considered great, it should do better. In the world today, you shouldn’t trust authors with quotes or facts by default. You should be suspicious by default unless an author earns more trust. Many people believe DD has earned a lot of trust (including me in the past), but they’re mistaken.

I apologize for encouraging people to respect and trust DD more than he merits. I know I played a role in that.

DD’s misquote problem also helps contextualize his recent mistreatment of me. How could a super rational, great person act like that? The answer is that he he’s actually a deeply flawed person with some good traits mixed in as special exceptions.

DD once got very upset with me for questioning a Godwin quote he sent me in a private discussion. He’d sent it without a specific source and I couldn’t find the quote by searching the book. It turned out that he’d quoted an obscure first edition but I was searching the third edition. He should have praised me for looking for errors instead of getting defensive and lashing out at me. Good scholars don’t expect to be trusted and don’t mind being questioned or challenged. Even though he didn’t misquote in that instance, DD’s irrational attitude was a warning sign that DD might be a misquoter. I failed to recognize the full problem and I didn’t go fact check his books at that time (2011).

BoI has an errata page (mirror) which documents a bunch of errors in the book. They are mostly factual errors, and the number and severity should concern readers. Despite all the misquotes in the book, there are currently no misquotes on the errata page, which says something about how little fact checking the book has been getting (there are probably a bunch of other errors that no one has found yet).

I will edit my book recommendation articles to warn people about DD’s misquotes. I will also take down the beginningofinfinity.com website that promotes BoI and put a warning there about DD’s misquotes.

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Update, 2021-07-12: In a 1985 physics paper in a prestigious, peer-reviewed journal, David Deustch misquoted Alan Turing.

Update, 2021-07-13: I made two videos related to DD misquotes:

Video about the Feynman misquote: "Science is what we have learned about how to keep from fooling ourselves.". This video goes into more depth.

Video about this blog post about DD's misquotes. This video is more of a broad overview.