French physicist and media star loses doctorate after plagiarism investigation
science.org
science.org
Plagiarizing from people on your own thesis committee is a wild move.
I can't read enough French to understand every detail, but the plagiarism report shows that he was rephrasing all of the sentences rather than copying verbatim: https://v42.arretsurimages.net/fichiers/documents/2024-08-02...
He wrote the thesis at a time when it was impossible to identify lightly rephrased statements across a wide body of works. Now we can dump all of these documents into an LLM and have similar sentences surfaced for human review very quickly.
At the same time, it's no longer necessary to pick sentences from other people's work and change the phrasing. You can take someone else's paper, feed it into an LLM, and tell it to rewrite it for you. Easier than ever before to launder text.
The article doesn’t really expand upon what having fragments copied from others means. Even if it fits the letter of the definition, on a phd thesis that may or may not be a big deal. If he’s passing off the ideas of others as his, or faking his research by using the results of others or making them up, then that’s really bad. If he’s just using phrases / wording from others to get his original points across, it looks bad but I don’t see it as a huge deal, especially 30 years out from the phd.
A PhD is supposed to be original research, if the originality or integrity is in question that’s one thing, the rest is much more pedantic, even if technically wrong.
They link to the document that shows the plagiarized sections side by side with their sources
https://v42.arretsurimages.net/fichiers/documents/2024-08-02...
I don't read enough French (especially at PhD thesis level!) to parse everything, but even I can see phrasings copied from the source documents in a lot of the examples. Some of them weren't even paraphrasing, they were lifting the exact distinctive word choices.
(Another one, unrelated, but also wild, argues that people who attack him are in fact against science itself, that they want to go back to the Middle Ages, etc.)
It's very obvious he pieced together interesting ideas from others to pass them as his own. And it worked very well, he has radio shows and TV shows and whatnot. And he still has a lot of supporters!
Also, being able to get ideas, synthesise them and present them in a way palatable for mainstream audiences is a useful skill and an important role in society. It’s just not research.
Fun fact: he's using this to prove he didn't do anything wrong, as in "see? the people on my thesis committee didn't care I copied their own work, why should anyone else?"
The truth is, people on "thesis committee" don't read thesis. Some do. The director usually does, if he has the time. But many don't; they glance at the intro and conclusion and call it a day.
> He wrote the thesis at a time when it was impossible to identify lightly rephrased statements across a wide body of works. Now we can dump all of these documents into an LLM and have similar sentences surfaced for human review very quickly
He also uses this to say it's unfair to punish him now with tools that didn't exist when he did the crime, which I find quite rich. If you murdered someone before DNA testing was available, that doesn't exonerate you in any way.
What exactly is the point of dedicating years of your life to create something exactly nobody is going to read?
1. literal stapler thesis, or
2. cleaned up version of a stapler thesis (e.g. rewrite of several previous publications to give broader context etc)
There's a lot to be said about publishing in academia being broken and how nearly all the value comes from 10% of publications, while the rest are garbage spewed out for reasons orthogonal to the advancement knowledge. However, IMHO, none of that really applies to PhD theses.
It's really the "cheat yourself" problem, except we put some value on that paper and those letters.
This definitely varies by field. For example, there are some branches of linguistics where the big, important new monographs that move the field forward are often PhD theses (though typically the defended diss manuscript will get some very light rewriting and polishing before it appears from a publisher). After that, a scholar's publications over his/her career might be less ambitious and focused more on minutiae.
But the process of creating that work, engaged throughought that process with those purported to be more practiced, is usually pretty good at seeding enough expertise and confidence that you might be able to proceed more independently and with real novelty, or might at least be prepared to share the trade with others new to it.
That's the point of those years, and so it's more than a little ironic that AI is being used to undermine a practicing expert while simultaneously eroding the traditional process for becoming one by making it so easy to just generate slop and engage with hallucinations than to actually practice writing deep work or engaging with primary sources.
It is not "early work" but the end of early work. The masterpiece: the piece of work that proves a subject has mastered their craft.
If you're still producing junk you haven't earned your PhD.
Then academia is broken and the universities that operate like this should be dismantled (not to mention the accreditation organizations)
What's actually happening is people chasing items on a CV instead of actual knowledge is rotting the core of universities.
If we apply your criteria, I'm not sure if any universities would be left.
I find it rich how fast you are to jump to destroying the entirety of academia in one stroke. It's quite easy to say things we don't understand should not exist, of course I'm guilty of this myself from time to time. Have you done education beyond the bachelor's degree? It's a very different world.
In some ways, people doing research now have it way more difficult than people of the past. They have hundreds of years worth of research to study before they are on top of things and making an original contribution that stands out among the huge amount of research that already exists is really hard. If we want to keep PhD as a proof of meaningful work, then we ought to lengthen the graduate studies considerably. How about a 10 year PhD program, at the end of which you can really say you have mastered the field?
You probably have plenty of novel ideas in early career, but you almost certainly lack the experience and the basic understanding of your field to develop them properly. Most people have exhausted their own ideas by mid-career. But that that point, they should have the skills and the experience to work on the ideas they come across.
(Looking back at my PhD, it's quite amusing how little did I understand. On the other hand, many of the choices I intuitively made turned out to have some value. But in some cases, understanding that properly took a decade of work by other people.)
Your PhD work is an apprenticeship, after which you are expected to work as a journeyman. The masterpiece that qualifies you for independent work as a tenured professor is often called habilitation. Many academic cultures don't have those, because the expectations are so situational that they don't want to formalize them.
introduction1 -> main1 -> conclussion1
introduction2 -> main2 -> conclussion2
introduction3 -> main3 -> conclussion3
the thesis is something like
long introduction -> easy example -> main1 -> main2 -> main3 -> main of preprint -> long conclussion
It's a long time that the incentive and job structure make universities a very toxic environment. Professors are basically running a 40 years race (about from bachelor or master graduation to retirement). It is still amazing that some good comes out of it.
For me, it wasn't quite so apparent at the defense, and I don't know that all members read the final thesis carefully, but most of them had already seen me publish or present most of the research previously, often multiple times. I also know that some (and not just my advisor) did read the final thesis very closely. My thesis was only partially thesis by publication, however, which may have influenced this; it does now have a fair number of citations in its own right, which is somewhat unusual for the theses in the field, and potentially seen as awkward (it means there's significant work in the thesis that I never published elsewhere).
As a caveat, the American system (before current crises) does feel like it can have a two-tier system of PhD students who are expected to remain in academia (we both were) and ones who are not, even at strong universities. Expectations, and attention given, can vary considerably. The American system also tends to have larger and more closely involved committees than, for example, the UK/Irish system.
However, for the form of plagiarism discussed here: if someone had sentences from papers I published years ago interspersed in their work, and they weren't particularly notable sentences, I'm not confident I would notice. Depending on citations and what the sentences were, I'm not even sure I'd mind much, for example, if they were essentially copying a model definition.
Also, very dry, so it's easy to loose focus, and you can read a rephrasing of your own thesis as a "he has the same ideas" (also, if you do that, please reference the author?)
I find a few of the example damning (hje should totally have added a citation and build his argument around it). Most less so, and i understand that a reader could not catch them.
I don't know about this case, but a lot of these kinds of cases truly are witch-hunts. It's not at all like the reproducibility crisis and faked data and images.
With another professor I caught a flagrant case in a student thesis and we faced attacks from the university administration because the student had a stellar transcript (also not the positive signal some might think). Punishment was almost inexistent.
It's difficult for me to imagine what it would take to get a doctoral thesis revoked.
If some in your experience erred on the side of leniency, then it stands to reason that others might err just as egregiously in the opposite direction.
In fact, your anecdote suggests erring is the norm. We should thus expect punishments to be inappropriate in one direction or another. An appropriate punishment seems rather unlikely.
Universities and other similar large institutions usually err systematically in one direction - that which protects the institution.
Personal grudges. Academia is full of them.
No respect for the plagiarist physicist, but an easy way to control what media representatives of scientific disciplines get to say publically, is to start out with what amounts to "academic compromat" (scientific fraud, plagiarism, ...).
Did this physicist / media star recently say something controversial?
I mean why did the system let him pass as a physicist, and why did it let him rise the media rank?
Not really. This is the consequence of an investigation by some journalists about a decade ago, and an audit that lasted for almost 2 years.
> I mean why did the system let him pass as a physicist, and why did it let him rise the media rank?
He is a smooth talker and by all accounts good at vulgarisation. He does well in interviews and is easy to deal with for journalists. There’s always been controversies but media thrive on those.
They compiled a document with the source material side-by-side https://v42.arretsurimages.net/fichiers/documents/2024-08-02...
This goes well beyond accidentally triggering a plagiarism detector.
> Feed stuff you wrote into those tools and it will call you a plagiarist every day because you wrote something similar to the person you learned it from.
The examples in the article use very distinctive wording. One or two occurrences would be forgivable as coincidence or inspiration. An entire document full of examples points to something else.
This wasn't a couple cases of the same words or word pairs being used.
People say how obvious the parlor trick is when they look at a small model LLMs. Well, I've seen the same parlor trick in students who get good grades but seem weak at thought from fundamentals. It seems quite possible to me that in some examples we are now going after them because the environment changed. At much earlier points we did actually value the people who could recite even if somewhat brokenly because we lacked random order recital tools.
Sadly, this idiot won an award before I was able to see their work, so they had the confusion of receiving an award, and THEN being told they were being spanked for unacceptable behavior. Since they were too stupid to hide the most blatant clues, they had a hard time comprehending this duality.
I imagine any tool that’s good at plagiarism detection would also kill it at this kind of literature research.
An example of something where it worked like this is that I had some ideas around how tribes evolve and so on and wrote them as I could think of them and ChatGPT was able to find that Darwin’s Cathedral had a far better synthesis of various much more rigorous takes on the subject.
These tools compare words, not idea. They would not detect someone copying concepts but coming up with their own words. I guess some specially fine-tuned LLMs could work but I am not aware of a company actually licensing those for plagiarism detection.
This is just how scholarship works. It's not needed in the kind of day to day most of us do, but when you're writing a thesis for a PhD, this stuff matters. You're making the argument that you're expanding the totality of human knowledge with your dissertation, and that requires strict source citing to separate your original scholarship from the sources that influenced it.
There have been a lot of plagiarism accusation in his books already. In this case there was an audit and the conclusions are clear. Whole paragraphs copied and pasted word for word without attribution, about a third of the document overall. If anything, this should have happened about 15 years ago.
What crime?
Just to put it side-by-side in a form that will absolutely not work on mobile but might work if you're on desktop, here's a "two-column form" of an example plagiarism from the thesis:
[ THESIS ] [SOURCE]
les équations de la physique engendrent, les équations de la physique engendrent,
en plus des solutions correspondant aux en plus des solutions correspondant aux
phénomènes, des solutions sans aucune phénomènes, des solutions sans aucune
signification physique directe. signification physique directe (certaines
solutions sont rejetées, par exemple,
parce qu'elles violent la causalité
usuelle). La correspondance entre les
mathématiques et la physique n'est donc
pas biunivoque et naturelle. Ceci laisse
donc planer un doute sur une sorte
Un doute
très sérieux plane donc sur l'idee d'un
isomorphisme entre le language mathé- d'isomorphisme entre le langage (mathé-
matique et la nature. Quant matique) et la nature. [...]
à l'explication platonicienne de la L'explication platonicienne de la
réussite des mathématiques réussite des mathématiques peut être
divisée en deux thèses. La première
pourrait être qualifiée de « platonisme
faible » (celui qui peut être trouvé dans
des dialogues tels que la République).
elle consiste à admettre que
les mathématiques Selon cette conception, les mathématiques
constituent un langage intermédiaire qui constituent un langage intermédiaire qui
permet de passer du monde sensible au monde permet de passer du sensible aux monde
des Idées, qui forme la réalité profonde des Idées qui constitue la réalité profonde
des choses. Si les mathématiques sont des choses. Les mathématiques sont
efficaces, dira un platonicien, c'est efficaces ici
parce qu'elles permettent de viser les parce qu'elles offrent unmoyen de viser les
structures profondes du monde. véritables structures du monde.Also, I believe citation is usually limited to prior written work. I don't think citing personal communications is mandatory, but at least for me lots of ideas come up in personal communications, random discussions, etc.. I think actually we should give more credit in this case, but it shows that attributing fraud for failing to cite may be a little too harsh. Again, I don't know if that's the case here, or if his thesis is just some pastiche or prior work without any significant or original contribution.
Just some Google Translate of some of the plagiarized paragraphs, the thesis "The Unity of Physics" has:
> The idea that the diversity of reality is underpinned by a deeper unity is as old as thought itself. Great mythologies recount it, early philosophers affirm it, and modern science has taken up the same agenda by first unifying concepts of motion, matter, and space. Indeed, the desire for intelligibility can arguably not do without the idea of the One. However, simply attributing such a tendency to human nature does not validate its realizations. The proclaimed unity may well prove false—stemming merely from incantation, decree, or fantasy—while exerting a purely dogmatic fascination. Yet, if thought were to discover—amidst the shifting mirrors of phenomena—eternal relationships capable of encapsulating them, one could certainly speak of a joy of the mind. While not necessarily an essential framework of thought, the desire for unity corresponds to a nostalgia, a craving for the absolute, an ontological impatience. Yet, the moment it is expressed, it clashes with the irreducible dispersion of things. From this arises a rift between the desiring mind and the disappointing world. At the close of the century, the increasingly assertive power of physical theories—with their all-encompassing nature and unifying aim—prompts us to examine the foundations of the physicists' quest for unity, to define its limits, and to consider its current prospects.
This is claimed to be a mashup of paragraphs from three different sources, first, the sentence starting "However..." is said to hail from Jean-Michel Besnier's "Theories of Knowledge",
> Could the "monist" tendency inherent in the act of knowing be suggested any more clearly? Yet, simply positing such a tendency within human nature is obviously not enough to validate its realizations. Indeed, that unity may well prove illusory, stemming from sheer fantasy while exerting a purely dogmatic fascination. That is precisely why critical philosophy sets out to distinguish between the scientific and...
Followed by a bit of Camus' "Myth of Sisyphus,"
> If man were to recognize that the universe, too, can love and suffer, he would be reconciled. If thought were to discover, within the shifting mirrors of phenomena, eternal relationships capable of summarizing them—and of summarizing themselves in a single principle—one could speak of a happiness of the spirit of which the myth of the blessed would be but a ludicrous counterfeit. This longing for unity, this craving for the absolute, illustrates the essential movement of the human drama. Yet the fact that this longing exists does not imply that it must be immediately appeased.
The last sentence of Sisyphus was changed except for the "Yet" to what appeared to be an original sentence or two in the thesis, "Yet ... irreducible dispersion of things. From this arises a rift between the desiring mind and the disappointing world" -- but only to immediately jump into a third line from Parrochia's "Grand Revolutions of the 20th Century,"
> The increasingly assertive power of modern physical theories—along with their all-encompassing nature and unifying aim—now enables the scientist to occupy, to some extent, the role held by the philosopher from antiquity through the classical age. This is by no means the least significant consequence of the revolution we have experienced...
My very very initial read of this style, I would almost guess that he paid someone else -- someone who did not have a science education -- to write his thesis for him. And probably if that were true, then he had to provide the sources, "I like this sentence from here, that one from there, you see I highlighted this paragraph of this paper -- I'll highlight and you just paste everything together into one big whole and I'll look through the word processor and tweak a couple of sentence beginnings and endings to make everything look nice for the committee and probably only one person on the committee really reads a bit of it but let's be honest that they're all busy with their own research." With that sort of origin, that's how you get the "blind copying without rephrasing" type of thing (The person who's copying doesn't trust their technical chops to rephrase anything! "What if I choose the wrong word and it has another meaning in science and I embarrass myself?" -- so they go verbatim, "this made sense to someone who was well educated in the sciences, it can't be too embarrassing") with a little bit of tweaks between the chunks.
The really incredible thing about the plagiarism report is the 16 copié-collé/copy-paste sections AFTER this one, where it's just like "Yep, he stole whole pages at a time from his sources in just this way."
That is his defence:
"Having read many books throughout his career, he may have “assimilated” them and “not always consciously” used them in his own writing, he said."
I have never published anything in academic context, but I did write a lot and I often found that phrases of the same topic I read before creep into my own writing, so I could see this happening to me without intention.
"the plagiarism report shows that he was rephrasing all of the sentences rather than copying verbatim"
On the other hand, this is in fact the standard defence when someone is accused of plagiarism. But sometimes it might actually be correct? (No idea here, my french ain't good enough either)
In general the reaction seems out of proportion to me, I much rather would like to have focus on actual fraud in science.
I sometimes read this blog for example and there seem to be other things going on with less attention.
A lot of times when I read certain plagiarism examples (Claudine Gay for instance)
Like plagiarism seems like it can happen for three reasons:
1. You intentionally tried to take someone else’s effort / ideas and make them your own. Real bad
2. You were lazy didn’t read enough to know to attribute correctly. Not great?
3. You were writing about a set of ideas that only have so many ways to express them. You really didn’t know.
I’m not saying we should give plagiarism a pass but maybe a statute of limitations? It seems really hard to tell 20 years later. Because to a certain extent - is this a case of 1? Did he pass of effort as his own? Or, if he has attributed Camus would you say “fair ‘nough mate, wasn’t central to your innovation”
Maybe we need to assess every paper ever written and figure out which percentage can be accused of plagiarism. Intuitively it seems like the number would be high.
But yes, in general, I do think a LOT of academics could be accused of the milder forms of plagiarism if you scrutinized all of them.
The plagiarism will be something like "Einstein presented a new theory: ___" and the ___ and several sections of the next few pages will be barely modified Einstein quotes.
Should they have used quotation marks? Technically, yes. But using them breaks up the flow for the reader, and it's not like they are failing to give credit to Einstein.
As an academic, I really would not care much if someone did this to my work so long as they mention and cite me generally.
It’s not the case here.
> The plagiarism will be something like "Einstein presented a new theory: ___" and the ___ and several sections of the next few pages will be barely modified Einstein quotes.
Again, that’s not the case here. There was no attribution, no reference, and no quotes, for entire paragraphs. About a third of the thesis overall.
> As an academic, I really would not care much if someone did this to my work so long as they mention and cite me generally.
Which is fine, but again not very relevant to this case.
I guess nowadays it is much simpler to correlate some text with prior work, more so with LLMs. It is like those doping cases where several years later we are able to detect a previously unknown sustance in an old sample.
It is worrisome that the scientific machinery as it stands needs an overhaul in LLM era.
If anything, the charge has even more gravity now since now you were too lazy to use an LLM. Kinda like when you see bad English in an Amazon product listing and wonder if you even want to buy from a company who was too lazy to use a free LLM to fix up the copy.
If the ecosystem required copy and paste to discover copied ideas, then it was doomed long ago and it’s a good thing that the AI era finally forces real process change.
It can be as unobtrusive as putting a simple footnote after each of those paraphrased blocks of text, thus only appearing as tiny numbers in the text.
If Klein had just done that, he would have escaped this kind of accusation, while not changing a single character of his books as they are currently written -- except for the tiny footnote numbers. The footnotes contents can also be gathered at the end of the book, and this is completely normal.
And there is nothing wrong with a text full of footnotes. That's really the standard, actually, in books targeting advanced readers, such as students.
If one does that, assuming citations are not the bulk of the work, one should be in the clear.
If it is rephrased, you cannot just put quotation marks.
But you still have to indicate the source of the rephrasing (especially when it is lightly rephrased) e.g. by a footnote.
God damn¹, Louis XIV’s country that inspired La société du spectacle to Guy Debord is actually a great place to make a career as a courtesan, who would have guess.
Guillotine images in streets are also on the rise: I can no longer make the smallest road trip without seeing some plastered all around.
Looks like neither the wanna shine as elite in the bonnes gens side nor the drive me to unsustainable pauperized state in the crowd can refrain from their extreme propensities.
¹ https://www.capmemo.fr/sciences-humaines/983-le-mariage-de-f...
² https://en.wikipedia.org/wiki/The_Society_of_the_Spectacle
I don't know much about how one gets a PhD, but I assumed it involved the thesis committee reading your thesis? They didn't notice their own work?
Did they not notice? Is that because they copied it off sometime else!?!
2. Well, at least it's an option in their back pocket, if they ever need to get out of a regretted contract or tenure commitment.
3. The article mentioned "weekly radio show". While presumably not the case here, the idea of academic as public public influencer suggests that rogue politicians could use allegations of academic plagiarism (due to LLM) to neutralize an academic who is saying something they don't like, when funding levers can't be used.
(Examples of topics for academic positions that some politicians might not like: climate change, race/ethic, sex/gender, geopolitic, safety scandal of campaign donor, planetary flatness.)
(I'm guessing this attack might work, since academics tend to profess more (dare I say it) conservative ideas about integrity than the overall population, and the universities value their own reputations highly. And academics have some rules and hierarchies, and they enforce rules when a transgression is called out in a way that can't be ignored. So, even if the general population goes full AI acceptance of people putting their name as author on things that aren't their own work, you'll have a lot of academics holding their own to a higher standard. And they already have a belief that plagiarism is bad. Fabrication is another bad. Popular LLMs are currently spewing both heavily.)
Is he actually a physicist, as the article says? If so, I don't see that the title is misleading.
I suppose it could say "French physicist loses philosophy doctorate after plagiarism investigation" but it would probably lead to a different sort of confusion.
As much as ~60-70% of current academia leaders have bogus credentials and engage in plagiarism (from their colleagues, students, etc...).
It's just terrible, we live in a modern dark ages because of this.
Cheating in life isn't necessarily that bad, if you are at the end of your studies and it's either you pass by cheating, either you don't, then the only logical thing to do is to cheat, who would go in more debt and potentially ruin their live doing otherwise, and WHY?
Recently a Harvard president, Claudine Gay was sacked.
Also Francesca Gino was also punished for her (alleged still ? ) fabrication of data.
So what's the problem ?
But Gay's PhD was not revoked.
https://aaas.fas.harvard.edu/people/claudine-gay
So Harvard employs, as a full professor, someone whose Ph.D. thesis contained loads of plagiarism (I’ve seen the evidence, it’s not contestable). A similar offense on the part of the students who sit in her classroom, according to Harvard’s own rules, could lead to expulsion.
EDIT: Also, as pointed out in a comment below, Prof. Gay’s Ph.D. is from Harvard. It was not revoked.
I remember it was technically initiated by the Harvard business school, but it was probably triggered by data colada launching their own investigation.
This speaks to your point.
Borg?
These kind of people are just deluded manchilds which can't accept how the universe works at all. They thing everything orbits
For a bit of an equivalent more US tech people could appreciate, he's kind of the national local Lex Friedman. He initially focused on this domain but then gradually had more and more famous guests across any field where he didn't have the required expertise.
Never heard of him
If his supposed popularity is coming from a spot on France Culture, I understand why I'm not familiar with him or his work
Are you suggesting he isn't actually popular or rather than you do not listen to France Culture or yet something else?
I'm a bit confused as it's quite easy to check that he is indeed famous (again, not claiming it has any consequence on this work) in France related to popularizing science. I would bet, but feel free to ask around, that most people interested in scientific popularization know of him, but please do ask around, I'd be curious if it's just in my social circles.
And I don't watch TV so it won't help either.
After posting my first comment I actually did asked, first at work and later to friends/family ; the only positive answer was from someone who listen to France Inter daily. Otherwise they said they never heard of the guy.
Actually it's an interesting topic because it's far from the first time that I see some journalist talking about "someone famous", and yet I never heard of them.
It seems that there's actually no real "mainstream medias" like it used to be when I grew up, where the vast majority of people were watching the 20h everyday. Talking to adults in their 20s is quite illuminating. Things we could consider "mainstream" are unknown to them. They don't even know they exists.
FIP is cool, I even have a shortcut to play/pause it from anywhere on my system using 'mpv https://stream.radiofrance.fr/fip/fip.m3u8 --no-resume-playback'
...so he's an entertainer for the masses, if you get your science knowledge from these medias I have bad news for you.
PS: FWIW I repeated in multiple posts that it was solely about popularity, nothing else, but I can make this explicit here again.
They know of him because he's going on lots of radio stations/tv channels.
They haven't expressed any opinion on what they think about the guy.
That being said, I suspect people in ASI can read Liberation, so they would know that Etienne Klein comes from a Catholic family [1].
Names can be tricky : the founder of the site is called Schneidermann... and yet he had troubles with Israel nationals... [2]
[1] https://www.liberation.fr/futurs/2016/10/23/etienne-klein-il...
[2] https://www.franceinfo.fr/faits-divers/police/la-police-appe...
Shall we now impute dishonor on all those whose past writing cannot pass an AI examination? Do we start with Isaac Asimov, Carl Sagan, George Gamow, Michio Kaku, ...?
In any case, we need to hurry. You may not care, but there is some jackass in France who is losing sleep.
So many things in physics have to be written in a very specific manner , to convey the meaning of the precise concepts being used. in such cases, it is a very common practice to copy the sentences used before, in order to ensure that everyone understands the meaning in a precise manner.
So then to call it plagiarism doesn't make any sense
2. If you need to use the exact same phrase as someone else, then you should cite them