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Dennis Hackethal, Plagiarist

Dennis Hackethal (DH) published the book A Window on Intelligence: The Philosophy of People, Software, and Evolution – and Its Implications on 2020-03-13. The book heavily plagiarizes Elliot Temple (ET, myself) and David Deutsch (DD, who was ET’s mentor, colleague and close friend for over 10 years). DH repeatedly uses their ideas without giving credit and tries to present them as DH’s own ideas.

DH came to ET in Dec 2018 and initially treated ET like a mentor he was thrilled to have found and be able to learn from. Finally DH found an expert who knew a ton about the topics DH was interested in, and had good ideas instead of bad ones (in DH’s opinion, most experts are terrible, but DD and ET have great wisdom). And ET was actually accessible to learn from, unlike most experts! DH joined ET’s discussion forums and got lots of learning help. DH left after 5 months (DH stopped using the forums and stopped speaking to ET or ET’s associates) and DH refused to say why. That’s around the time DH started writing the book. Later, posting elsewhere on the internet, DH communicated that he has a hateful attitude towards ET and ET’s associates (even though DH still seems to be a huge fan of their ideas and even filled his book with their ideas). Despite cutting contact, DH continued reading ET’s writing.

The below post goes over some examples of how DH’s book plagiarizes ET and DD, and also does some copyright infringement. This is the sort of egregious, extensive plagiarism that gets people expelled from universities. It’s not just a little bit. The book should never have been published and should be withdrawn from the market.

There's also a video where I watch and comment on Justin reading and commenting on this post.

Even though the book has a bunch of ET’s ideas in it, DH provided ET no opportunity to comment before the book was published, did not provide a courtesy copy to ET, and didn’t even notify ET about the book’s existence after publication. This is after DH had personal tutoring sessions to learn from ET, discussed on ET’s forums and his chatrooms, and more. He directly learned material from ET, put it in the book, and didn’t even notify ET, in addition to not giving credit in the book.

Despite relying so much on ET’s and DD’s ideas, DH still introduces a bunch of his own mistakes. The book may alienate readers from the ideas in addition to stealing credit.

Part of the problem is DH’s incompetence. He had no business writing a book. He doesn’t know how to cite things. He screws up badly when speaking about some Richard Dawkins material. He flames Nick Bostrom inappropriately. He gives DD credit in a few places, often inadequately, but then gives zero credit to DD in the majority of cases. However, it’s not just incompetence. DH’s intentional malice is clear because, for example, ET’s name literally isn’t in the book even once, even though it’s packed with ET’s ideas. Details for all of these points are covered below.

DH’s response to the issue is also covered below. He admits he screwed up and expresses his confidence that the book has lots of plagiarism. DH says he’ll fix the plagiarism if ET finds it for him, but then immediately breaks his word and refuses to even read documentation of the problems that he’d just requested. As unbelievable as this is, it’s all documented below since DH put it in writing.

As a likely further response, this website was DOSed (sent extra traffic to break the website so pages don’t load) shortly after DH saw a draft of this blog post, but before it was posted. Whoever did that is a criminal and the timing of the DOS seems unlikely to be a coincidence. The DOS was presumably done by DH or someone he told about his plagiarism. I don’t recall this website ever being intentionally DOSed before, while this DOS was clearly intentional (it’s not just e.g. a web spider ignoring robots.txt). For security reasons, I won’t provide technical details. I’ll just say the attack quickly made the website stop loading for anyone. If DH isn’t involved in this crime, he should provide the evidence he has about the crime, such as who he told about the plagiarism issue and thereby provided motive to. I’ve contacted DH about this. If DH won’t help catch the criminal, all civilized people should shun him even more than they should for his plagiarism. Note as context that DH has a recent history of breaking laws, associating with criminal(s), and lying in defense of criminal(s).

Note: I haven’t read much of DH’s book and don’t plan to. I just skimmed a few parts and searched for keywords. There are probably many other issues which I don’t discuss here. My impression from skimming was that there were a bunch more problematic issues that I didn’t read more about. The parts I comment on were easy to find fast. I did look at all instances of DD’s name (20), ET’s name (zero) and ET’s websites (3), so I know what credit was given to them. I didn’t check if other people like Karl Popper were plagiarized or not. The below is only lightly edited because it’s good enough to communicate the info and I want to get back to educational writing and philosophy research ASAP.

Copied Sentence

Yellow quotes like this are from DH’s book:

Criterion of universality – x is a universal y if it can do all the z’s all the other y’s can do

This sentence comes from when ET was teaching DH what universality is. One part of the educational help DH got was a discussion involving 20 emails. In it, ET wrote (Feb 2019):

X is a universal Y if it can do any Z that any other Y can do.

DH had trouble understanding. He wrote e.g. “I think I'm still confused about universality.”. But after further educational efforts by ET, DH understood the idea enough to copy that sentence into his book and plagiarize the topic in general.

I (ET) recognized this sentence immediately when I saw it. It was a major topic I educated DH about. The sentence is highly distinctive. This isn’t plausibly an accident.

Here’s another example of the plagiarism related to universality:

Whichever way one chooses to define domains in which to look for universality, it is crucial to pick useful qualifiers and determine meaningful domains.

This is an important idea (which is closely related to the Criterion of Universality above) that ET had to explain to DH multiple times before DH finally understood it. And the idea is original to ET, not common knowledge. But no credit is given.

Plagiarism and Copyright

Plagiarism is taking credit for ideas or writing that isn’t yours. Plagiarism is DH’s main offense. It’s the thing that gets people flunked out of university classes for being unethical.

Copyright protects the specific form of a work but not the ideas or concepts. It’s the thing that gets lots of YouTube videos taken down and people get sued over it. It’s a well known law in widespread use.

So DH could write about a criterion of universality in his own words and it would only be plagiarism (if he didn’t give credit) but not copyright infringement. But when he uses ET’s words in his book without quoting them or giving credit, then it’s copyright infringement. To avoid breaking the law, DH has to write his own words instead of borrowing sentences that ET wrote. (The slight rewordings don’t make it OK. You can’t get around copyright that easily.)

Note that copyright has an exception called “fair use”. If DH had quoted ET’s sentence and said ET wrote it, then it wouldn’t be a copyright violation, even without ET’s permission to use the sentence. Fair use allows quoting a little bit of someone’s writing for e.g. critical commentary or educational purposes, but it doesn’t allow taking credit for other people’s work.

Copied Question and Plagiarized Chapter

It is essential to ask, “hard to vary given what constraint?”.

Those quote marks indicate dialog or speech, not a quote from another author. But it’s actually an exact quote from me, without credit.

I wrote it here (2019-06-01) and more prominently in this blog post (2019-07-17) where I was discussing with Bruce Nielson, an associate of DH who is named in the acknowledgments. Even if I hadn’t told this directly to DH’s associate, we know DH kept reading my blog even after he stopped discussing with me because he uses later material from my blog in his book.

Much of the rest of the chapter is paraphrasing ET without credit, such as this sentence:

We want an implementation to be hard to vary while still solving the problem(s) it purports to solve.

ET has said things like this many times, e.g. a 2011 formulation on the FoR email group:

knowledge is information that is hard to vary while solving the problem [that it’s designed or adapted to solve] equally well or better.

Although DH’s phrasing is based on ET’s writing, much of this concept was originated by DD. DD isn’t credited for it either.

The chapter has one footnote about one specific idea:

I first came across the idea of using multiplication as an example of knowledge in computer programs here: http://web.archive.org/web/20190701184215/https://curi.us/988-structural-epistemology-introduction-part-1, which is in turn based on the concept of structural epistemology, which goes back to David Deutsch and Kolya Wolf.

DH doesn’t give any credit in the main text and doesn’t give my name or a direct link to my website. And DH understates how much material he got from ET’s posts (of which there are three other main ones, on the same topic, that ET emailed to DH, by DH’s request, on 2018-12-24. The posts supplemented the discussion where ET taught DH about it verbally.)

With just this one cite and no mention of ET’s name, DH spends most of ch. 3 explaining ET’s work (some of which, as ET has acknowledged, DD helped with or originated; DH doesn’t credit DD either). DH borrows extensively from ET’s way of teaching and explaining these issues, for a whole chapter, and provides just one endnote mentioning where he got the general idea of using multiplication as an example. But ET didn’t just mention multiplication would be a nice example, ET gave examples and showed how to use them to explain some big ideas, and DH is plagiarizing all that (with, as usual, some added errors mixed in, and some key ideas omitted, so it’s screwed up but still easily recognizable as based on ET’s work).

Other ET Endnotes

The easiest way to find more plagiarism of ET is to check the endnotes. There are two more which indirectly reference ET’s website while refusing to give his name. First:

[33] Hans Hass, “The Human Animal,” as quoted on http://web.archive.org/web/20190702162345/https://curi.us/272-algorithmic-animal-behavior

You’d never know from this endnote that ET has made multiple videos about this specific topic and had multiple discussions about it. ET’s educational material is where and how DH learned what to say about the Hans Hass quotes he borrowed from ET’s blog post (just like DH was only able to partially understand universality due to ET’s educational efforts, for which no credit was given).

Hans Hass gets his name in the main text of the book too, not just in the note, as is appropriate. But ET’s name isn’t in the book once.

The whole section on ‘Animal “Learning”’ is heavily based on the ideas of ET and DD, including ET’s category of blog posts about animal intelligence. ET also has made several videos on the topic, had several debates, and had many earlier discussions about it on the email forums. They are distinctive ideas which DH plagiarized.

We can explain this easily and well through the existence of an inborn pathfinding algorithm whose results just need to be stored in memory for later retrieval.

DH got this specifically from ET. DH didn’t know it until ET taught it to him personally.

Before learning from ET, DH actually had conventional/mainstream views about animal intelligence. No credit is given for radically changing DH’s conclusions on these matters and teaching him the entire point of view he’s writing in the book.

The last endnote related to ET is:

[36] As far as I am aware, the notion of such a meta-algorithm was first introduced in the form of a “fail-safe” (but its significance underestimated) here: http://web.archive.org/web/20200207181124/http://curi.us/2245-discussion-about-animal-rights-and-popper

This includes an unargued, unexplained, unreasonable claim that ET made a mistake! ET’s extensive knowledge of an obscure subject is not evidence that ET underestimates it. ET’s bringing up something original (as DH believes it to be) is not evidence that he doesn’t realize it’s significant.

Again ET’s name isn’t given and this is only an endnote so a reader could easily never realize that even this little bit of partial credit was given. DH uses the term “meta-algorithm” 95 times in the book, inspired by ET and no one else (according to DH’s own account), but doesn’t give ET meaningful credit. I actually think DH is confused about the issue and its originality (it’s already in widespread use by programmers, which DH apparently hasn’t noticed, but certain applications of it to animals are original to DD and ET), but I won’t get into it more.

Note that the link here goes to a post ET wrote in Nov 2019, over six months after DH had stopped speaking to ET without explanation. It shows DH was still reading ET’s work and using it for his book, including specifically ET’s posts relating to animal intelligence.

Another plagiarism example is DH’s discussion of golden rice and the precautionary principle. Is it a coincidence that ET wrote about golden rice and the precautionary principle, also in Nov 2019 while DH was reading ET’s work and writing the book? That ET post also explains a non-standard view of Pascal’s Wager and then DH writes something similar about Pascal’s Wager in another part of the book. DH did change it by incorrectly lowercasing the “w” in “Wager”, even though it’s a proper noun.

DD Plagiarism

I skimmed DH’s book and noted a few topics discussed which are distinctively associated with DD. Then I searched for every time DD’s name was used to give DD credit. Subtracting the times DD got credit from the list, the rest are plagiarism.

Topics plagiarized from DD include: Problems are soluble, problems are inevitable, various universality stuff including the jump to universality (using DD’s exact phrase "jump to universality” seven times), reach, and criteria for reality. These are major ideas from DD’s books, especially The Beginning of Infinity (BoI). They are highly original and distinctive ideas which DH gives zero credit for. DH’s book title “A Window on Intelligence” is also based on DD’s chapter title “A Window on Infinity” in BoI, without credit.

Topics where DD got some credit include: Structural epistemology, hard to vary, universal explainers, static and dynamic memes, Church-Turing-Deutsch principle, and "If you can’t program it, you haven’t understood it.”. In the first 3 of those 6 cases, DD’s name only appears in an endnote, not in the main text of the book, so most readers still won’t know it’s DD’s idea. Also there’s no text crediting DD for the Church-Turing-Deutsch principle, it’s just implied by DD’s name being in the principle’s name. But Deutsch is a pretty common name and there’s no mention it’s the same guy and no citation to DD’s book, BoI, where DD talks about it as the “Church-Turing conjecture” (so DH is using material from DD’s book, with no cite to the book or explicit credit, and DH changed the name, which is a typical example of how he distorts the ideas he plagiarizes enough to screw them up a bit while still leaving them recognizable as other people’s ideas).

There’s also an endnote linking to a DD blog post. I didn’t read that part of the book to investigate further.

Besides the list of plagiarized DD topics above, all the other DD topics in the book are also plagiarized, since they aren’t some of the few topics where credit was given.

The appropriate action is to credit DD by name in the main text every time one of DD’s major ideas is introduced, at minimum. As a comparison, in The Fabric of Reality (FoR) DD shares a few criticisms of Thomas Kuhn, who is a relatively minor topic (the index indicates that Kuhn comes up on only 11 pages in a 22 page section of the book, and isn’t mentioned at all elsewhere). Nevertheless, Kuhn’s name is used 26 times, while DD’s name is used 20 times in DH’s book where DD is basically the main theme of the whole book. (I don’t think it makes much difference to this comparison because Kuhn only comes up in one part of the book, but FYI DD’s book is around 40% longer than DH’s.)

Misrepresenting Association with DD

From the acknowledgements:

David Deutsch, whose books were some of the inspirations for this book, for tirelessly answering my many questions over the years.

This isn’t true. I have lots of info about this from both DD and DH. I’d rather not get into personal details about the relationship between DD and DH unnecessarily because I know DD generally prefers his life isn’t made public. I’ll provide more info if DH disputes my claim that his statement is untrue. (I’ll interpret that dispute as DH wanting this to be a public matter and granting permission to share everything he told me about it, so it wouldn’t even be a little bit discourteous to share.)

Speaking generally about info that’s already public: When DD actually tirelessly answers questions over many years, you end up with e.g. ~8000 emails from him (over half private), like I have, as well as millions of words of personal chat logs. DH has nothing like that. If DD actually was interested in talking with DH much, then DD would be credited for reading and commenting on some of the book, too. If he tirelessly answered many questions, why not read the whole book? But surely DD’s unlimited energy would extend to commenting on some book material (which is presumably some of DH’s highest quality writing, so some of the stuff DD would most want to read or respond to). DH hardly knows DD and is trying to exaggerate a name drop in order to climb the social status hierarchy.

DH, btw, contrary to various pro-criticism and pro-reason themes of his book, has actually admitted to me that he’s a social climber who cares deeply about public perception of him. DH doesn’t want anything negative said about him regardless of whether it’s true or false. I’m under no obligation to keep those particular messages private, but am sticking to only a paraphrase as a courtesy since they aren’t currently available by Google search. I’m not exaggerating. If DH denies this, I’ll provide exact quotes.

Feynman the Popperian

Feynman was familiar with Popperian philosophy and even taught it (though not without mistakes).

Source: Me? (Regarding Feynman’s familiarity with Popperian philosophy.)

AFAIK I’m the only person to publicly make that claim (until DD joined my discussion to back me up). And I, unlike DH, gave sources and evidence.

I figured it out from Feynman’s books but DD already knew it from talking with Feynman IRL and also from DD’s knowledge of the physics community. I shared the idea and many people thought I was an idiot until I convinced DD to share part of his knowledge too.

As to Feynman teaching Popperian philosophy, that’s a misleading exaggeration from some little fragments Feynman taught. And, despite being the source of the idea, I don’t know what mistakes DH is talking about and he doesn’t explain or give any source.

Here, again, DH uses me or DD as an unacknowledged source but then screws the idea up some too. He uses enough of our idea that it’s distinctive and recognizable, but also throws in stuff we don’t agree with. So giving credit would be problematic because DH doesn’t separate what he got from us from his own misconceptions.

Sources: I have a blog post Feynman the Popperian from 2008 but the main material is on email discussion groups, particularly the Fabric of Reality (FoR) group based on DD’s book. Yahoo recently deleted the archives for all groups but you can get the archive from my ebooks page.

I also told DH about this directly, e.g. from 2019-03-03 I told him “i think Feynman read and understood Popper well.”

Here’s DD posting to the FoR group, 2011-05-02, responding to one of my critics. The quote DD responds to is cut from the middle of a paragraph in a rant directed against me:

On 2 May 2011, at 3:41pm, John Clark wrote:

There is in fact no hard evidence that Feynman even knew that a fellow by the name of Karl Popper ever existed.

For what it's worth, I happened to mention Popper in the one conversation I had with Feynman, sometime in the 80s, and he did not say "who's that?" but replied meaningfully to the point. So that's evidence he had heard of Popper at that time. What he knew of him, I have no empirical evidence of, because Popper was peripheral to the conversation and I never got round to pursuing the matter.

Wheeler, on the other hand (my boss and Feynman's thesis advisor and subsequently his collaborator), knew a lot about Popper and was honoured and delighted when Popper quoted one of Wheeler's aphorisms as a chapter epigraph. Wheeler and I discussed Popper in detail on several occasions and I tried to persuade him to become a Popperian -- ultimately without success, because he preferred Polanyi (!). Nevertheless there were specific aspects of Popperian philosophy of science that he very much agreed with, especially that scientific theories are not derived from anywhere, that they are conjectural and full of errors, and that science makes progress by correcting these errors.

-- David Deutsch

(For what it’s worth, DD told me what he and Feynman said to each other. I consider that conversation fully convincing that Feynman knew a ton about Popper, but unfortunately DD prefers not to share the details publicly.)

DH Is Incompetent at Citation

[6] Karl Popper, “Back to the Presocratics”

[10] Karl Popper’s translation in “Back to the Presocratics”

These citations do not follow any of the standard style guidelines for cites. Nor, worse, do they provide enough information for someone to find what Popper wrote. DH gives the name of an essay without saying what it is (book, essay, TV show, what) or saying what book it can be found in. DH elsewhere cites books and TV shows using the same format (quote marks around the title) that he here uses for citing an article within an unnamed book. In those cases, at least he’s giving an author and the overall title of the thing in question, so it’s less bad. Here he left out the name of the book he’s citing!

DH even screws up referring to his own writing:

Dennis Hackethal, Misconceptions About Evolution, 2020

Dennis Hackethal, What Is the Difference Between a Person and a Recording of That Person?, 2020

What book, journal or website has those articles? All DH gives is a title but no link or indication of what type of work they are. It’s not enough info to look them up and read them.

People who don’t know how to cite – and are unable or unwilling to learn or to use a tool that creates properly formatted citations for you (those tools are readily available for free) – should not be writing books with 86 end notes and 35 bibliography entries. Maybe if DH had learned the basics of what he was doing before publication, he would have found out what plagiarism and copyrights are in addition to how to cite, but instead he acted irresponsibly and unethically.

DH Is a Jerk

Although large portions of the book are about DD’s ideas, Nick Bostrom, who is brought up as a target to attack (not as a source of ideas DH advocates), is named more times than DD. Here’s a sample of what DH says about Bostrom and his book Superintelligence:

Oxford has produced … some of the worst [intelligence research] (Nick Bostrom).

Bostrom is [a] slave of [irrational ideas]

[Bostrom’s] book is such a nauseatingly pessimistic attempt to snuff out AGI

[Bostrom’s] book is a slaveholder’s manual. To say this is not an exaggeration, nor is it metaphorical

[Bostrom’s book is a] Gestapo-style manual

DH does give some intellectual reasoning related to these attacks. I think the reasons are partially right but I also disagree significantly. The reasoning is unfair to Bostrom and would be inadequate to make these attacks even if DH was right about all the issues. If you read the book to see the context of the Bostrom quotes and understand the arguments, you may agree with DH’s claims somewhat more, but you won’t find they get any nicer.

Lots of the reasoning DH uses for attacking Bostrom on AI alignment and slavery is plagiarized from ET. DH also plagiarized the view of a new AGI as similar to a child needing an education. Comments like “If you build an AGI, you are a parent.” are taken from ET. (The AGI material is easily recognizable and distinctive while also being changed enough to screw it up). BTW, elsewhere DH also brings up parenting to talk about it being an area heavy with static memes, which is again something he got from ET.

DH also slanders the U.S. south and other slave-holding societies throughout history, by implication, by suggesting that slaveholders only ever gave slaves the minimum food/shelter/etc. to keep their slaves alive to get acceptable work out of them.

A slaveholder needs to keep his slaves alive so that they continue to work for him. He improves their wellbeing only to the point where they can perform the work to an acceptable degree. This degree can be much lower than what promotes comfort or health, resulting in tremendous suffering.

Although I’m not a fan of slaveholders, this is an unfair attack that doesn’t accurately represent slavery throughout history. There have been many times that slaveowners were kind to slaves and even voluntarily freed them. Not all slaves were horribly mistreated (some were horribly mistreated, e.g. in the silver mines of ancient Greece, including too often being mistreated to the point that they didn’t stay alive, contrary to what DH says). I suspect DH is thinking in terms of game theory but hasn’t read about slavery in actual societies.

Richard Dawkins

Another odd use of the concept of slavery is:

the evolutionary biologist Richard Dawkins discovered that organisms are protective shields genes build around themselves. Organisms are the slaves that genes use to spread through the population.


Like all organisms, human bodies are the slaves that genes use to achieve this purpose.

First of all, the term “survival machine” appears 96 times in Dawkins’ book, The Selfish Gene. That’s why I still remember it even though I haven’t read the book for many years. Why doesn’t DH use the right term? The term “shield” is only in the book once in a different context (DNA membranes). Dawkins’ term is more accurate and descriptive, and somewhat different (a machine does more than a shield, e.g. machines have moving parts and could plausibly hunt for food, while shields don’t). DH has distorted Dawkins’ viewpoint and is getting stuff wrong even before the stuff about slaves.

The stuff about slavery is confused, is a poor explanation of survival machines, and is being unfairly associated with Dawkins, who never said it. To make it harder to tell that Dawkins never said it, DH gives no cite here, not even mentioning which of Dawkins’ books he’s talking about.

Not being plagiarized by DH is a mixed blessing because he misrepresents people’s views when he does name them.

Dennis Hackethal’s Comments

I contacted DH when I first saw a major issue in the book, which was the criterion of universality issue. He responded agreeing that he was in the wrong and that the book should be changed. He also informed me of his belief that his book had many more problems of a similar nature. He asked me to do the work of documenting them for him and send him all of the problems at once.

In my reply, I provided DH with what he’d asked for. He wanted a bunch of problems at once instead of one by one. He had said he would review what I sent him. I sent him a pre-publication copy of this blog post which wasn’t very different than the final version.

DH replied that he wouldn’t read or review any of the plagiarism problems with his book because he didn’t have time – which means because there were too many problems with his book, so it was too much to read. But he’d asked for everything at once, and I didn’t even send him anything near a comprehensive review of the book’s errors. Rather than read whatever amount he’d been willing to read (e.g. only 5 problems for the whole book?), he decided to read none of them.

Besides breaking his word about reviewing the problems I sent him at his request, DH’s reply also said he’d consulted a lawyer and implied that he would only deal with copyright violations not plagiarism. The unstated reason is that copyright violations break the law while plagiarism is unethical but is not generally against the law. So DH is knowingly and intentionally a plagiarist. I tried to double check this with him but he didn’t reply.

I know this is shocking beyond belief so here are quotes. Here is DH agreeing that he made a mistake about the criterion of universality:

it looks like you did tell me that [sentence], in which case the right thing to do is to credit you

He then proposed to add an endnote, with no mention of mentioning ET’s name anywhere in the book, and while still leaving ET’s sentence in the main text of the book with no quotation marks, as if DH wrote it.

Here’s DH stating his belief that the book has more issues of a similar nature (copyright violation and plagiarism) based on incorrect speculation about how ET was reading it:

judging by the passage you're at, it looks like you're still pretty early on in the book. As I'm sure you will find more issues

DH continued with his request for information about the copyright and plagiarism problems to be sent all at once in one long document covering the whole book:

I suggest you finish reading the book so I can review your suggestions and make any applicable edits in one go.

Note how DH is “sure” there are more issues in the book, but intends to do nothing about them unless and until ET explains them to him. In the meantime, DH won’t even try to fix the issues in his book that he’s “sure” are there. (Of course it’s not ET’s job to point out DH’s plagiarism to him. ET did DH a huge courtesy by sending him lengthy documentation of some of the many plagiarism issues.)

In DH’s second email, he began by forgetting that he’d asked for all the info at once, and expressing his disinterest in revising his book to fix the plagiarism:

I don't have time to read your blog post.

He then brought up his lawyer and changed the subject to only be copyright, not plagiarism.

ET’s reply asked:

You only replied about copyright. Are you saying you’re unwilling to address plagiarism issues?

DH did not reply.

Want more proof? Here are screenshots of DH’s two emails. Email 1 and email 2.


DH’s book is full of plagiarism. He tries to pass off other people’s ideas as his own in order to manipulate public perceptions of him. He plagiarizes heavily from at least ET and DD (who have a bunch of important and original ideas that aren’t very well known, so they are particularly good targets to plagiarize). It also has at least two copyright infringements where it uses ET’s writing (as DH’s words, no quote or credit) instead of just copying and paraphrasing ideas from ET and DD without credit.

Although some of the problems are due DH’s incompetence, it was his responsibility to learn what plagiarism is and how to give credit before publishing a book. And surely he’s heard of plagiarism and could have investigated the matter before acting so unethically. And DH has done this partly maliciously and partly in an attempt to climb the social status hierarchy.

The book should be withdrawn from the market and would need massive revisions to be ethical. Ethically, it’d need to be withdrawn from the market while those revisions were made, otherwise DH would be intentionally committing plagiarism during that time. The revisions would also need to be documented so people would know what was changed and could check whether that was acceptable; hiding the version history of the book or being vague about the revisions would be unacceptable.

If you’re considering a business or personal relationship with DH, or an intellectual collaboration, or even just reading his book, I suggest you reconsider. If you’re already involved with DH, I suggest raising the plagiarism issue with him and then disassociating from him if you reach the conclusion that his plagiarism is extensive and indefensible.

DH received credible information that the book contained plagiarism, agreed that it did, stated he believed his book contained more plagiarism, asked to be told problems, received that info, and refused to read it. This is all on purpose.

I will update this post if anything substantial changes, e.g. if Dennis Hackethal stops being a plagiarist or helps investigate the DOS crime.

There's also a video where I watch and comment on Justin reading and commenting on this post.

Update 2021-11-08: I have been reliably informed that DH made a second edition of the book. He did not notify me or announce it on the book's website or, as far as I know, anywhere else in public. The errata page on the book website does not explain what was changed in the second edition. I don't know of any explanation or listing of what changes he made or why. Last I heard from DH, he refused to fix the plagiarism, as explained in my post above.

I own the book on Kindle (I paid for it; DH did not give me a courtesy copy or even notify me that he wrote it). I re-downloaded it previously after hearing vague rumors of a second edition, but I found that it wasn't updated. The situation on Amazon seems kinda glitchy. I think DH handled the new version incorrectly and screwed things up so that previous customers never got the updates. I don't have a copy of the second edition. I don't want to buy it twice and I'm not sure that trying to buy the same book again on Kindle would work correctly anyway. Based on limited information, it appears that DH made a few inadequate changes aimed at my complaints. My name is now in the book more than zero times, but he's still clearly biased against me. And my post (above) did not attempt to be comprehensive; it was just a few examples from skimming the book. My impression is that DH should have learned what plagiarism is and how it works, then made comprehensive changes to the book, but he didn't do all that. His changes look more like putting band-aids on some of the problems (similar to his recent blog posts, which sometimes plagiarize me and sometimes give me credit, with no clear pattern).

Elliot Temple on April 3, 2020

Messages (29)

If anyone has information that may be relevant to the DOS crime, please contact me. Does anyone know if there was any discussion of the plagiarism at any of the Four Strands groups? Full copies of that would be appreciated but even confirming whether it happened would be helpful.

FYI this blog post was put up around 11:15 AM, pacific time, on April 3, 2020. The DOS began at around 9:30 AM, around 45 hours after Dennis Hackethal received a draft version of this blog post.

curi at 11:28 AM on April 3, 2020 | #16248 | reply | quote


(This is the book review I posted on several sites. I guessed that including a URL was a bad idea but I'm not sure.)

This book contains extensive plagiarism of Elliot Temple (me) and David Deutsch (my colleague and mentor). Deutsch and I developed and published many of the ideas in the book which are presented as Dennis Hackethal’s own ideas.

Dennis learned not only from reading my work and watching my videos, but also from a personal mentoring relationship. I personally helped him learn about topics like universality, animal intelligence, Popper, Deutsch, and structural epistemology (the multiplication stuff). Then he plagiarized me on those topics and others. There are public records of many forum posts where I helped him learn this stuff over the 5 months leading up to around when he stopped speaking to me without explanation and started writing the book, around a year ago. I also helped teach Dennis in private chatrooms and on voice calls. My name does not appear in the book once.

Here is an example of the plagiarism. Me teaching Dennis: “X is a universal Y if it can do any Z that any other Y can do.” We had a lengthy email discussion about this idea and a voice call about it too. Dennis struggled to understand it.

Then the book says, “Criterion of universality – x is a universal y if it can do all the z’s all the other y’s can do”. No credit is given and it’s presented as Dennis’ own words, not as a quote.

Ideas plagiarized from Deutsch’s books, with zero credit, include: problems are soluble, problems are inevitable, the jump to universality, reach, and criteria for reality.

I initially contacted Dennis about the plagiarism privately, even though he didn’t even notify me the book existed even after publication. He responded indicating that he had gotten a lawyer and would not read my explanation of what he plagiarized. Then my website went down due to a DDOS attack.

curi at 11:59 AM on April 3, 2020 | #16249 | reply | quote


> In January 2019 you [Dennis Hackethal] reached out to me on Twitter asking about my business ideas for a collaborative problem solving platform. I shared them with you during a long Skype call. I hope you haven't borrowed any of these [for the forum you made] without asking permission?

DH replied "Hehe". He also denied it. In his denial, he made claims about where his inspiration came from which omitted the significant role of FI.

Anonymous at 4:46 PM on April 3, 2020 | #16252 | reply | quote



Anonymous at 7:18 PM on April 3, 2020 | #16254 | reply | quote

Inductivism plagiarism example

Found this while streaming and watching Justin's video from #16257


DD in BoI:

> *Inductivism*   The misconception that scientific theories are obtained by generalizing or extrapolating repeated experiences, and that the more often a theory is confirmed by observation the more likely it becomes.

Dennis Hackethal in WoI:

> *Inductivism* – The misconception that we create explanations through induction and that theories corroborated by observation are more likely to be true

If you don't see the issue, or for more info and detail, see my on-stream explanation. It starts roughly 50 minutes into the stream and goes ~10min.

curi at 2:09 PM on April 4, 2020 | #16258 | reply | quote

Other people have previously called the Turing Principle the Church-Turing-Deutsch principle, such as Michael Nielsen


Nielsen actually credits DD, unlike Hackenthal who just ripped off DD.

oh my god it's turpentine at 2:53 PM on April 4, 2020 | #16259 | reply | quote

The way FS ppl will ignore indisputable facts (which they make no attempt to dispute) like the plagiarism stuff and the Andy stuff is similar to this:


People ignore facts from Project Veritas, which are caught on camera, just because they are biased against Veritas.

Joe Rogan says:

> even though you see it on video, you hear people say things that should be outrageous to anyone who believes in objective reality, and yet people love to say 'that’s just a Project Veritas thing,' 'that guy's full of sh*t,' and they’ll say 'that guy's full of sh*t, good' and they cast it aside.

curi at 5:25 PM on April 4, 2020 | #16261 | reply | quote

Why do you constantly refer to "plagerism is what gets people kicked out of university" is it appeal to authority?

Mingmecha at 4:18 PM on April 9, 2020 | #16329 | reply | quote

#16329 Twice isn't constantly; you sound hostile.

You're misquoting the post and being careless with spelling; you don't seem like you actually care to think about this matter.

Dagny at 4:22 PM on April 9, 2020 | #16330 | reply | quote

Updated blog post with this line, near the start and at the end:

There's also a video where I watch and comment on Justin reading and commenting on this post.

curi at 5:00 PM on April 18, 2020 | #16388 | reply | quote

Here's an example of a gaming news/info company, with an audience, staff and resources, plagiarizing a small YouTuber (who had 3 million views on the year old video the ripped off) for content.

The plagiarists also incompetent and thoughtless. In a different video they took something from the same channel in a way that made no sense – they got a clip from a video on X topic so they assumed it was about X topic even though it wasn't. It was an unrelated clip used for a minor side point.


And more about it:


curi at 6:46 PM on April 22, 2020 | #16419 | reply | quote

curi.us is being DDOSed again using the same method as the DDOS that happened right before I put this post up. It's likely the same person: Dennis or one of his associates who Dennis is intentionally sheltering by withholding information (so Dennis is at least a DDOSing accomplice, today, by intentional choice). The info Dennis is withholding is who he gave advance, pre-release information to about the plagiarism blog post, thus giving them motive. He also hasn't even denied being the DDOSer nor made any statement asking his fans or associates not to DDOS and disowning such actions. Instead he has a history of taking actions to encourage and participate in targeted harassment that crosses the line into illegal initiation of force (Dennis spread lies about specific false facts about me in order or to defame me – and then he admitted his claims were untrue when I found out and asked if he had any sources).

curi at 10:42 AM on May 15, 2020 | #16536 | reply | quote

Amazon Deplatforms My Review

> From: community-help@amazon.com

> Subject: Important Information About Your Posts

> Hello,

> One or more of your posts were found to be outside our guidelines. In order to help our customers make informed choices, we encourage them to review the product and contribute information about it. However, Community content that violate our guidelines or Conditions of Use will be removed.

> Please consider this a first warning.

> Before submitting your next post, please refer to our Customer Guidelines:

> http://www.amazon.com/gp/help/customer/display.html/ref=hp_508088_bid_1594471?nodeId=508088

> Failure to comply with our policies may result in your account being banned from taking part in Community features.

> Thanks for your understanding in this matter.

Belatedly (two months) Amazon has decided to engage in censorship of negative information about books. They gave zero information about what I did, which content they're talking about, what rule it broke, etc. The only reason I know what they're referring to is that the one review is the only thing I posted to Amazon this year.

Amazon didn't just opt not to post the review like Barnes and Nobles. They threatened to ban me from leaving any reviews. That's way worse.

curi at 10:37 AM on June 4, 2020 | #16608 | reply | quote

#16608 Meanwhile I see that the book is apparently no longer for sale on Amazon or Apple.

curi at 10:41 AM on June 4, 2020 | #16609 | reply | quote

If you never learned about plagiarism in school, you can practice online: https://ca.ixl.com/ela/grade-12/identify-plagiarism

Anonymous at 2:37 PM on June 30, 2020 | #16815 | reply | quote

The only review on Amazon mentions a section "evolution of creativity". Ch 16 in BoI is "the evolution of creativity".


Anonymous at 4:53 PM on July 2, 2020 | #16829 | reply | quote

Also, it's not entirely out of print - I was just able to buy it on kindle and download it immediately.

It's curious to think about what might happen if there were youtube-esq copyright protocols for books; amazon being a major vendor means it'd be much easier to implement now than in the past.

max at 4:58 PM on July 2, 2020 | #16830 | reply | quote

DH gets the publication year of BoI wrong (2012, not 2011). Not even sure how you do that.

Anonymous at 5:00 PM on July 2, 2020 | #16831 | reply | quote

Video about IGN's content theft:


Anonymous at 6:29 PM on July 9, 2020 | #16862 | reply | quote

Hackenthal's book still on Amazon, in print and kindle editions, and with a 5 star review from Logan Chipkin. There is also a website for the book and Hackenthal is publishing articles referencing it:


What a complete low-life.

Anonymous at 12:49 AM on July 28, 2020 | #16927 | reply | quote

my opinion FWIW

I think the cases cited are not really bad plagerism as he's rephrased things.

HOWEVER, it's really bad form to present ideas as your own that you got from others. You should always cite your sources. It seems Dennis hasn't done that, which is a big no-no in academia.

I have purchased the book and will be reviewing it soon on Amazon. My general impression of this book from listening to his podcast etc is that it greatly over-sells itself and doesn't present a balanced view on things or how to define various terms.

Dan Elton at 5:38 PM on September 2, 2020 | #17768 | reply | quote

> HOWEVER, it's really bad form to present ideas as your own that you got from others. You should always cite your sources. It seems Dennis hasn't done that, which is a big no-no in academia.

That's what "plagiarism" means.

E.g. New Oxford Dictionary, "the practice of taking someone else's work or ideas and passing them off as one's own".

curi at 5:42 PM on September 2, 2020 | #17769 | reply | quote


I have the book in-hand now and am currently on Chapter 3, so I am looking at more than just the tiny snippets that have been pulled out here. It appears he cites stuff very thoroughly , I would say as well or better than most academics. Nobody cites every single idea they got from previous thinkers, the key is to cite key ideas and not make it look like you came up with major ideas that other people did not. Also, you only need to cite the major idea the first time it is mentioned - later repetitions, riffs, or variations off that idea don't need to be re-cited. As far as I can tell, Hackethal does a good job. Nobody is perfect, of course, and I'm sure ET is right on a few points. However ET's standard is starting to look a bit absurd / too demanding. Dennis makes it excruciatingly clear he got a lot of the core ideas from Deutsch and he also credits discussions with ET himself in a few places. So ET's complaining is starting to look pedantic and a waste of time to spill ink over in light of this.

Dan Elton at 5:54 AM on September 21, 2020 | #18096 | reply | quote


which edition of the book do you have? It'll say on the page with the publishing details.

plagiarism is yes/no. either DH did or didn't; the length of the book might mean it's easier to make a mistake, but it's still that: a mistake, and still plagiarism.

how did DH respond to ET?

curi said:

> Besides breaking his word about reviewing the problems I sent him at his request, DH’s reply also said he’d consulted a lawyer and implied that he would only deal with copyright violations not plagiarism. The unstated reason is that copyright violations break the law while plagiarism is unethical but is not generally against the law. So DH is knowingly and intentionally a plagiarist. I tried to double check this with him but he didn’t reply.

DH didn't want to do the right thing. He knew he was doing the wrong thing.

curi said:

> I will update this post if anything substantial changes, e.g. if Dennis Hackethal stops being a plagiarist or helps investigate the DOS crime.

DH presumably hasn't contacted ET.


Apparently there was a second edition published June 2020:

The publishing page reads:

> First edition March 2020

> Second edition June 2020

Searching this edition:

I can't find 'criterion of universality' in the book, and skipped chapter 4 and couldn't see the quote ET has up.

Also a ctrl+f for 'qualifiers' didn't show anything either. (The quote ET has up under criterion of universality)

DH's acknowledgements at the beginning also (now?) have

> David Deutsch, whose books were the main inspiration for this book, for answering my many questions.

So DH tried to fix the issues ET brought up -- 2-3 months later. I don't know about other examples or how else the book has changed.

Max at 6:25 AM on September 21, 2020 | #18097 | reply | quote

Dennis Hackethal is such a plagiarist. He just keeps writing about my stuff with no acknowledgment. After heavily plagiarizing my stuff about animals in his book, he recently did a blog post on the same old, obscure declaration that I had blogged about:



He also wrote criticism of Ayn Rand which probably-not-coincidentally is one of the main topics I've criticized her about. He uses some arguments I've made at https://blog.dennishackethal.com/posts/objectivism-vs-the-myth-of-the-framework

curi at 1:17 PM on May 22, 2021 | #20573 | reply | quote

The DDoS of my website started when I sent Dennis Hackethal a draft of the above blog post (at his request), but before I posted it. He is either the DDoSer or he's an accomplice who is hiding information about who the DDoSer is by refusing to share information about who he shared my draft with. DDoSing is a serious crime.

The circumstances under which I sent him the draft of the blog post are that I contact people privately about problems before complaining publicly. Dennis replied to my initial complaint and said he'd fix stuff but wanted it sent all at once instead of one issue at a time. But then his response to my draft post was to say it was too long so he wouldn't even read it. Ridiculous.

curi at 1:22 PM on May 22, 2021 | #20574 | reply | quote


This post attacks teachers who claim to understand and value TCS. That is a theme I've written about before. Also, what teachers do that? The only one that comes to mind is Brett Hall. Brett's teaching has been critically discussed on list before (Brett quit FI because he wanted sanction and approval from TCSers for his teaching).

Is Dennis attacking Brett Hall without naming him – using a point I've written about – because he's jealous that Brett is currently getting a bunch of undeserved clout and social status and Dennis isn't?

Also a minor thing: people like Dennis and Rami copy me so much, e.g. by writing comments on their own blog posts (including old ones), which I do a ton but which is not typical.

Dennis also tried to create forum software based in substantial part on my ideas about how to do a discussion forum.

curi at 1:26 PM on May 22, 2021 | #20575 | reply | quote

Want to discuss this? Join my forum.

(Due to multi-year, sustained harassment from David Deutsch and his fans, commenting here requires an account. Accounts are not publicly available. Discussion info.)