Last week, I wrote about the mistake that Neil deGrasse Tyson made by appearing on the podcast of antivaccine leader and influencer Del Bigtree. In brief, I argued that it is, with only rare exceptions, a very bad idea for a scientist, physician, or science communicator to agree to debate a science-denying crank like Del Bigtree. It doesn’t much matter what the specific variety of science denier is, either. They can be antivaxxers, cancer quacks, climate science deniers who deny that human activity is causing major changes to earth’s climate, or creationists who deny evolution. The general point is that a scientist, by appearing on the same stage or on the same venue as the science denier, automatically elevates the science denier’s status by giving the false impression that there is a real scientific debate to be had over the topic in question. Moreover, although I can (somewhat) understand the temptation of a physician, scientist, or science communicator not to turn down challenges to “debate,” I always caution that such a temptation is very often at least as rooted in ego and fear of being portrayed as a coward “too afraid to debate” than it is in a genuine—and misguided—belief that debating the crank will change minds and have one iron principle that I suggest to people who won’t listen to my advice and decline debate invitations: Do the “debate” in a neutral forum with as close to a neutral moderator as can be agreed upon. Do not go on the crank’s radio show, podcast, or whatever venue, where the crank controls the narrative (and even the camera angles). deGrasse Tyson ignored all those principles. Worse, although he was, as usual, very good on “big picture” topics, he was woefully unprepared for specific conspiracy theories and misrepresentations of science that were very predictable to who has paid attention to Del Bigtree.

I don’t want to belabor points that I made in more detail in my lengthy post last week about the debate. Rather, I want to focus on one specific topic where deGrasse Tyson did both very well in concept but also did poorly in that he didn’t seem able to grasp how his argument would be received by Del Bigtree and his audience. I refer to the concept of scientific consensus, which deGrasse Tyson emphasized a number of times throughout the nearly two hour spectacle. The reason, of course, is that nearly by definition science denying movements reject the current scientific consensus. Because they reject the current scientific consensus, they often feel obligated to go beyond that and reject the very concept of a scientific consensus at all, emphasizing individual scientists who made discoveries that radically changed the scientific consensus throughout history, such as Galileo (who is invoked so often by science deniers that I coined a term for them referring to Galileo, specifically the Galileo gambit, way back in 2005), Albert Einstein, and the like. (Oddly enough, antivaxxers almost never mention Louis Pasteur as an example, probably largely because they often attack him or falsely claim that he “recanted” germ theory on his deathbed as a strategy to deny germ theory.)

In brief, the science denialist view of science is very individualistic in a manner that basically rejects science as a collective enterprise designed to come to an agreement on principles and understandings of specific natural phenomenon in favor of what I like to call the “brave maverick.” Indeed, worse than that, the science denialist view portrays scientific consensus as not just antiscience, but as a “manufactured construct” for The Man to use to suppress “dissent.” Not that “The Man” is not just limited to the scientific community but all power structures in society, something that deGrasse Tyson clearly did not comprehend.

Let’s explore this concept a bit more than I did last time, something I decided to do when I saw a post on the Substack of Maryanne Demasi, Scientific consensus—a manufactured construct. In my last post, I also briefly quoted longtime antivaxxer James Lyons-Weiler’s expressing similar concepts in his Substack post What Neil de Grasse Tyson Does Not Understand About Science.

Cranks react to Neil deGrasse Tyson’s appearance on The Highwire

In my post last week, I did point out how the one clip that went the most viral, that circulated the most widely in antivax circles, was a five-minute clip in which deGrasse Tyson emphasized the scientific consensus on vaccines. I’ll post a representative Tweet from the same day that video of the debate was first posted online:

Notice the quote featured by the antivaxxer:

I’m not interested in medical pedigree. I’m interested in medical consensus and scientific consensus…The individual scientist does not matter.

While I expressed approval of the general sentiment expressed, I also noticed that it was the last blunt part about how “the individual scientist does not matter” that provoked so much opprobrium from antivaxxers, who howled about it as evidence that deGrasse Tyson was interested only in defending the scientific status quo against “inconvenient” science from their brave maverick doctors and scientists. Of course, ignored by antivaxxers is just how much deGrasse Tyson tried to explain how scientific consensuses evolve and how difficult it is to determine when the anomalous findings of an individual scientist or group of scientists are just a fluke versus when they are harbingers of more findings that force a change in the scientific consensus, as well as how a new scientific consensus still has to account for the old scientific consensus. One example he used is how at velocities that are very small fractions of the speed of light—that is, pretty much all velocities that humans commonly encounter in their day-to-day existence—predictions by the Theory of Relativity become indistinguishable from those made by Newtonian mechanics because the relativistic contributions are so small that they round to zero. Appropriately, deGrasse Tyson pointed out that Newtonian physics were more than good enough to get us to the moon.

Now, let’s look at what Maryanne Demasi has to say. I will first, however, note that she recently featured in this very blog because Peter Gøtzsche had teamed up with her, despite her long history of antivaccine propaganda, to write a review article that exaggerated the risks from COVID-19 vaccines.

She gives away the game in the opening passage of her post:

In a recent interview, famed astrophysicist Neil deGrasse Tyson was challenged on his scientific views about COVID-19 and he said “I’m only interested in consensus” – words that would have Nicholas Copernicus and Galileo Galilei rolling in their graves.

Whenever an antivaxxer or other form of science denier invokes Galileo, I like to point out that Galileo actually didn’t contradict a scientific consensus but rather the religious dogma, regarding the universe, which was geocentric—i.e., stated that the earth was the center of the universe and that all other celestial bodies rotated around the earth—rather than heliocentric, a model in which the earth revolved around the sun. Indeed, as soon as they had access to good telescopes, Jesuit astronomers replicated Galileo’s results and some of them were even sympathetic to his new hypotheses. Antivaxxers and cranks love to cite Galileo, but they misrepresent his history as that of a lone scientist with a correct new theory being suppressed by other scientists. Interestingly, Pope Urban VIII had even given Galileo permission to publish about the Copernican model, as long as he treated it as a hypothesis; that is until Galileo went too far.

What really got Galileo into trouble was not so much his advocacy of a heliocentric model of the cosmos, which was being argued in scientific circles at the time, but rather how much he tweaked the Roman Catholic Church. Indeed, the first time Galileo was accused of heresy by the Inquisition in 1616 resulted in no punishment as long as he didn’t continue to advocate for the heliocentric model. (It also resulted in the Congregation of the Index banning all books advocating the Copernican system championed by Galileo, which it called “the false Pythagorean doctrine, altogether contrary to Holy Scripture.”) However, in 1632 he published his Dialogue Concerning the Two Chief World Systems, a fictional account of conversations between a Copernican scientist named Salviati, an impartial scholar named Sagredo, and an Aristotelian advocate of a geocentric universe named Simplicio, who was portrayed as a ponderous and intellectually inept fool whose arguments were systematically refuted and even ridiculed. Let’s just say that the Inquisition did not appreciate this book. Galileo was threatened with torture, tried for heresy, and required to “abjure, curse, and detest” his opinion that the sun was at the center of the universe. He was also sentenced to prison, but this was later commuted to house arrest, under which Galileo lived the rest of his life. The story of Galileo is, as you might expect, far more complex than just a scientist persecuted for proposing an unpopular hypothesis; much of what happened to him had to do with Church intrigue and his going too far in mocking the rival hypothesis that had been adopted as religious dogma by the dominant church, and it has also been noted at the time that Pope Urban VIII had been under attack by Spanish cardinals for being too soft on heresy.

I discuss this in detail again mainly because I haven’t done so in a long time and because the full story of Galileo is inconsistent with the simplistic ideological view espoused by people like Demasi.

Ironically, Demasi is close to correct when she writes:

A widely accepted theory, such as the theory of evolution, depends on a consensus being reached among the scientific community, but it must be achieved without censorship or reprisal.

Unfortunately, she couldn’t resist prefacing this statement with:

The appeal to “scientific consensus” is fraught with problems, just like “the science is settled” and “trust the science” and other authoritarian tropes that have dominated the pandemic.

So close and yet so far. First, as I have argued before, a theory is the highest form of a statement about how a natural phenomenon works that I like to characterize or define as the current best understanding of the phenomenon addressed. Indeed the theory of evolution is a good example, and it is not for nothing that it is often referred to as the central organizing principle of the science of biology. Demasi is also so very, very close and yet so far from an accurate statement of what a theory is in that she admits that consensus is required for a theory. However, instead of just coming out and saying that a scientific theory is a consensus (which it is), she has to qualify it as requiring that a consensus be reached by the scientific community and then adding that that consensus must be achieved without “censorship” or “reprisal,” going on to cite Dr. Aaron Kheriaty:

How many times have we heard variations on this particular sentiment from antivax cranks before?

Or sentiments like this one, from James Lyons-Weiler, which I’ll quote again at slightly more length because it is so much of a piece:

Del showed de Grasse Tyson an image of physicians and scientists they had on The Highwire, to which deGrasse Tyson responded:

“The individual scientist doesn’t matter”.

And he challenged Del to take the issue up with a “consensus expert” whatever that is.

The logical flaw is clearly obvious.

If, as deGrasse Tyson claimed, “The individual scientist doesn’t matter”, then Einstein’s singular work should not have been influential.

And if science is determined by consensus (which it’s not), then it’s “game over” once everyone agrees on something? We can lock up all the labs, and go home? We’re done? The best any human civilization will ever achieve is now?

At this point, that’s not just fallacious, it’s hubris.

This is what we in the biz like to call weapons-grade projection. After all, what is a better example of “hubris,” a scientist understanding that the scientific consensus regarding an issue represents the current best understanding of that scientific question, whose change will require evidence—and lots of it!—or the brave maverick who just “questions” the consensus and thinks that questioning, plus very little evidence, is enough? While it is true, as Dr. Kheriaty says, albeit misleadingly, that every major scientific advance involves a challenge to the prevailing scientific consensus of the time, it is not true that science has little to do with consensus, nor is it true that the consensus doesn’t change. It’s just that merely questioning the scientific consensus or pointing to single experiments is not enough.

I’m reminded of similar sentiments, often quoted by cranks, first voiced by Michael Crichton many years ago. Crichton, as you will recall, was a physician turned novelist who was also a climate science denier. Indeed, his novel 2004 State of Fear was basically a conspiracy theory represented in fiction in which eco-terrorists supplanted Al Qaeda—remember the year!—as the leading global threat plot to undertake weather modification schemes to convince the public of a nonexistent global warming threat. So what did Crichton say?

This, a quote that Demasi concludes her article with:

I want to pause here and talk about this notion of consensus, and the rise of what has been called consensus science. I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you’re being had.

Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.

There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.

Sound familiar? Crichton’s sentiment was, of course, utter bullshit, a complete misrepresentation of how science works. (There really is no more appropriate word to describe it.) Also note that even Crichton conceded that that the results of that “one investigator who happens to be right” must be “verifiable by reference to the real world,” which implies that even Crichton realized that anomalous results must be replicated before they can be accepted by science. I would counter that such replication is a collective exercise by scientists seeking consensus. Science has always been about seeking a tentative consensus understanding about the real world. It’s a consensus that can be changed—occasionally even by brave maverics!—but that change requires evidence. Anyone can question a scientific consensus, but it takes a lot more than that to overturn one.

In fact, I laughed at the tags applied to Crichton’s quote. They were very appropriate:

tags: 9-11, bisphenol-a, bpa, consensus, darwinism, dr-jack-cohen-podiatrist, evolution, excitotoxins, fluoride, global-warming, id, intelligent-design, macro-evolution, macroevolution, majority, majority-view, man-made-global-warming, manmade-global-warming, minority, minority-view, monosodium-glutamate, msg, science, scientific-discovery, scientific-inquiry, scientific-method, scientific-process, scientific-research, scientific-revolution, scientific-theory, september-11-attacks

Skeptics will recognize many of those terms as science denial, particularly intelligent design creationism and how it accepts “microevolution” but denies “macroevolution.” In particular, the tag on 9/11 amused me, given that it was almost certainly referring to various conspiracy theories that the attacks on the World Trade Center and Pentagon in 2001 were an “inside job.”

There’s a lot of Crichton in Kheriaty, to the point that this part doesn’t even make sense:

Those who defend scientific consensus rather than specific experimental findings are not defending science but partisanship.

This is such a nonsensical statement, even by Crichton standards, that there is only one correct initial reaction:

Godzilla facepalm

When Godzilla gives you the facepalm, you know the failure is monstrous.

There is so much fail in Dr. Kheriaty’s assertion. “Specific experimental findings” are often incorrect or can’t be replicated, for instance. Should I defend such findings over scientific consensus? Sometimes “specific experimental findings” come about as the result of poor experimental design and/or execution? Should I defend such findings—or at least refrain from criticizing them and pointing out the flaws in the experimental design and execution that produced them?

When it’s a battle of scientific consensus versus “specific experimental findings,” I’ll initially pick consensus almost every time, the exception being if those “specific experimental findings” are so compelling that they lead me to question the scientific consensus, something that is very difficult for one experiment or set of experiments to do. Indeed, deGrasse Tyson himself discussed this very issue, namely this question: How can one tell the difference between a finding in an experiment that is just anomalous and one that is a harbinger of more findings that will ultimately lead to major changes in the scientific consensus. It’s usually, although not always, impossible to tell at the time such findings are reported; often only in retrospect can we identify which experimental findings were the pebbles whose movement started an avalanche and which were pebbles whose motion disturbed nothing. In science, it is evidence that matters. It is also risible projection in the extremem for him to imply that those who defend “specific experimental findings” are not doing so because of partisan motives.

Concerning this emphasis on “specific experimental findings,” I remember how Robert F. Kennedy Jr. once teamed up with Robert de Niro (who is antivaccine) to issue a challenge: Prove the scientific consensus—in this case, with respect to the finding that the mercury in the thimerosal preservative used in some childhood vaccines until around 2001 do not predispose to or cause autism—and win $100,000. Let’s look at the wording of his challenge:

We hereby issue a challenge to American journalists (and others) who have been assuring the public about the safety of mercury in vaccines. We will pay $100,000 to the first journalist, or other individual, who can point to a peer-reviewed scientific study demonstrating that thimerosal is safe in the amounts contained in vaccines currently being administered to American children and pregnant women.

The conditions were as follows:

  1. Any individual seeking to collect the award (the Claimant) should submit, to the World Mercury Project (WMP), an English translation of the proffered study and a $50 processing fee (to discourage frivolous submissions from flooding WMP staff), along with a letter explaining why the study qualifies for the reward, and the name and address to which the $100,000 check should be directed.
  2. The study and corresponding evidence must have been published in a peer-reviewed journal appearing in PubMed.
  3. The claimant should submit a hard copy of the document and accompanying letter.
  4. To be eligible, the submitted study methodologies should be sufficiently transparent and the data available, to allow the judges to verify any statistical analysis upon which its conclusions rely. Only appropriately applied scientific recognized statistical methods utilizing reliable data will be eligible.
  5. Misters Kennedy and DeNiro will either pay the $100,000 reward check or send back a denial explaining why they believe that the study does not qualify. World Mercury Project will simultaneously post a link to the paper and text of the denial on the WMP website.

See the problem? RFK Jr. and de Niro proceeded from the false assumption that a scientific consensus about anything can established by a single study, which is almost never the case. It’s such a common line of argument among cranks, probably because it grossly oversimplifies the process of how a scientific consensus is reached, that I sometimes refer to it as the “One True Study” gambit.

As I have pointed out many times, there is never any one single scientific study or observation that by itself can conclusively demonstrate a scientific consensus. It’s almost never the case that any one scientific study settles a scientific question. Rather, in general a scientific consensus is established by many studies that usually include lines of evidence from different scientists and scientific disciplines that converge on a single conclusion, which becomes the scientific consensus. Similarly, a scientific consensus can in theory be overthrown by a single study, but that rarely happens either, if only because a finding that is so anomalous is more likely to be wrong than it is to be correct and will thus need replication. What usually happens is that a single study (or group of studies) cast doubt upon the existing consensus and lead to more studies that ultimately end up in its modification or rejection in favor of a new consensus. There’s a lot of big RFK Jr. energy in the reactions to deGrasse Tyson’s emphasis on the scientific consensus and emphasis on valuing rogue scientists and physicians (who are the usual collection of antivax cranks and quacks) and their bleetings and bad studies over a scientific consensus built on large amounts of evidence.

Scientific consensus as defined by cranks

The COVID-19 pandemic presented a once-in-a-lifetime (or even century) challenge to science in that the world was hit with a fast-moving pandemic due to a novel coronavirus whose characteristics were initially poorly understood. Unsuprisingly, antivaxxers like to focus on what was unknown about SARS-CoV2, the coronavirus responsible for COVID-19, and neglect something very important: Just because this was a novel virus did not overturn our scientific understanding of pandemics, public health, virology, other coronaviruses, vaccines, immunology, molecular biology, or infectious disease medicine built up over hundreds of years, much of which could be applied to this novel pandemic threat. Antivaxxers always seem to forget that scientists had been concerned about a global pandemic due to a new coronavirus ever since the SARS epidemic in 2003, which, fortunately, was contained. Moreover, even though many of us had been warning about the threat caused by antivaccine disinformation for years and years before the pandemic, public health authorities were largely shocked by its emergence and potency soon after the pandemic arrived.

Whatever the uncertainties in the science employed against the pandemic, one message of science deniers was very consistent, here voiced by Demasi:

It’s not difficult to reach a scientific consensus when you squelch dissenting voices.


Scientific consensus has become a manufactured construct, dictated by politics and power.

And reference to how she lost her job as a presenter in Australia years before the pandemic:

Several years ago, my successful career at the ABC came to a grinding halt after defenders of “scientific consensus” criticised several documentaries I produced, which questioned various medical orthodoxies such as cholesterol-lowering drugs, nutritional guidelines, and the over-prescription of medicines.

One of her reports fear mongered about wifi and cell phone radiation, leading to his amusing comment:

Critics complained that I’d given weight to a “fringe” position that was not supported by science. And by “fringe” they were referring Devra Davis, professor of epidemiology at the University of Pittsburgh, with a distinguished career at the National Academy of Sciences, and the National Research Council.

Let’s just say that we’ve written about Devra Davis’ fringe science and conspiracy theories on a few occasions here. If anything, she is a good example of deGrasse Tyson’s dismissal of credentials and emphasis on evidence when it comes to scientists bucking the scientific consensus.

As I like to say, it is not the questioning of a scientific consensus that is a problem. It is how you do it. If you do it based on credible scientific evidence, there might be pushback, but it’s not disinformation. I would also point out that many physicians and “conventional” scientists have “questioned” the overprescription of pharmaceutical drugs but have not been “canceled.” What starts to push a “questioning” of consensus into crank territory, into misinformation—or even disinformation—territory is when that questioning is rooted in conspiracy theories.

For example, here’s Lyons-Weiler:

Public health has of course done all it can do to prolong and delay the point between dissenting views and actual empirical data collection to try to refute and challenge the hypothesis under scrutiny. Collins and Fauci both argued for combined Phase 2/3 trials, ostensibly to reduce the time to EUA approval of COVID-19 vaccines. In detail, a Phase 1, Phase 2, and Phase 3 trial would allow a more thorough scientific process of finding and challenging adverse events via an attempt at replication: those found in Phase 2 could also be found in Phase 3.

That did not happen, and de Grasse Tyson likely does not know this, nor can he deeply appreciate the significance of that top-down move on the distortion of the results of the COVID-19 vaccine clinical trials: It delayed consideration until the “science” being done was observational, which leads to a causality stalemate (“correlation does not equal causation”). Collins and Fauci didn’t foster the necessary science: they destroyed it.

What Lyons-Weiler apparently does not know (or intentionally does not tell his audience) is that the idea of combining phase 2 and phase 3 trials into phase 2/3 trials is not a new one, nor is it unique to the pandemic. For example, here is an article discussing phase 2/3 trial designs…from 2008! It concluded:

A general conclusion is that, in many circumstances, a properly designed phase 2-3 trial utilizes resources much more efficiently and provides much more reliable inferences than conventional methods.

Basically, it is Lyons-Weiler whose understanding of clinical trial design is hopelessly out of date, as phase 2/3 trials are now common and generally an accepted method. Indeed, methodology has evolved to allow adaptive trial designs that combine phase 2 and 3, and a number of other variants. In other words, it’s Lyons-Weiler’s understanding of clinical trial design that is simplistic and out-of-date, not Francis Collins’ or Anthony Fauci’s understanding, nor was it a conspiracy to cut corners on the way to a vaccine. Combining phase 2/3 trials was a reasonable response to a pandemic for which a vaccine was desperately needed, not a conspiracy to get one approved based on poor quality evidence.

This is basically a conspiracy theory, and if you doubt me just check out how Lyons-Weiler embedded a 2021 Substack entry from Steve Kirsch into his post What really happened at Simpsonwood and why it matters today. The Simpsonwood conspiracy theory is really a blast from the past, being the topic of RFK Jr.’s infamous Deadly Immunity article from 2005. As I pointed out, the article discussed a CDC conference named after the conference center in suburban Atlanta in 2000 where scientists discussed data addressing the question of whether there was a link between thimerosal containing vaccines and autism risk and concluded that there appeared not to be an elevated risk associated with such vaccines. As I discussed at the time, thus was born through quote mining the Simpsonwood conspiracy theory, in which RFK Jr. and antivaxxers ever since have misrepresented statistical corrections for confounders as an effort to erase evidence that mercury in vaccines was responsible for an “autism epidemic.” In other words, Lyons-Weiler is referring to a 20 year old conspiracy theory to bolster his current conspiracy theory.

I’ll conclude by pointing out that I do not claim that science is perfect or that scientists are always open to evidence-based challenges to longstanding scientific consensus. Scientists are human, just like everyone else, and can be prone to the same sorts of biases and ideological blind spots that everyone else has. (One only has to point to the case of Ignaz Semmelweis, which was also more complicated than normally represented, but whose additional context does not exactly absolve the medical science of the time of guilt for how it reacted to his suggestion that maybe fewer babies would die if doctors just washed their damned hands after doing autopsies and before delivering babies, to see that.) The point is that cranks like Bigtree, Demasi, and Lyons-Weiler reject scientific consensus as a concept not so much out of intellectual honesty but because science rejects their pseudoscience and conspiracy theories. As a result, they elevate an individualistic view of science over science as collective study and understanding to a farcical degree in how they falsely claim that a scientific consensus is unchangeable, based on ideology more than science, and has a sole purpose of crushing “dissent.”

If deGrasse Tyson had understood this, maybe he wouldn’t have said something that, while technically not particularly objectionable to scientists (“The individual scientist does not matter”), was clearly something that antivaxxers would fixate on and misrepresent, which they did. It’s a shame, because in other ways he did a decent job of trying to explain what a scientific consensus is and how it can evolve based on experimentation and evidence. What happened as a result of his statement was entirely predictable if you understand how science deniers think. Is scientific consensus a “manufactured construct,” as Demasi claims? No more so than any other concept in science—or any other academic discipline—is “manufactured.”

The problem is Demasi’s understanding of consensus, as stated in a comment after her post:

I also agree that there has to be a way of reaching an agreement about the weight of evidence, my problem is with crushing dissent on the way there.

What do I mean? Cranks view any criticism or rejection of their views as “crushing dissent” rather than rejecting bad science. As long as that is true, they are likely to continue to reject the very concept of a scientific consensus in science. After all, the whole idea is to promote the idea that nothing is truly knowable, and the scientific consensus is an obstacle to that..


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