Deus ex machina

Many of you were too busy trying to ace organic chemistry to know what a deus ex machina is. For those of you who managed to squeeze in a classics course, please stick with me anyway.

Deus ex machina ("god from the machine") is a literary device. In ancient Greek literature, a complicated dilemma was sometimes solved by having one of the gods literally pluck the unfortunate protagonist off the stage from the arm of a crane. It's sort the ancient version of the Superman gambit---don't like the ending? Just turn back time by reversing the rotation of the Earth. In either scenario, an impossible dilemma is circumvented by an improbable escape.

I bring this up because the machina is also used in debates. A valid logical argument (OK, philosophers, please hold your horses...this is the 101 course) requires true premises and a conclusion that must follow. For example:

All humans are mortal

I am human

Therefore, I am mortal

The premises are very likely to be true, and the argument as constructed is valid. The conclusion is very likely true.

Mercury is toxic

Vaccines contain mercury

Therefore, vaccines are toxic

This argument is a properly constructed, superficially valid syllogism. If the premises are true, the conclusion is true.

But the premises are not true. Mercury is toxic---sort of, some of the time, in certain forms, in certain doses, delivered in certain ways.

Most vaccines no longer contain mercury.

Since the premises are invalid, the conclusions are false, despite a seemingly valid argument structure.

(Hmm, I didn't expect this post to go in this direction. Oh, well.)

Back to the machine. When debating various types of denialists, we skeptics are confronted with a problem. Whenever we present an argument that is valid and true, and the denialist can't seem to wiggle out of it--BOOM!--cue the pyrotechnics, and wheel in the machina. The most potent of these machines is the conspiracy theory, because they are always presented as unfalsifiable arguments, that is, not matter what you say, the denialist can respond, "Yeah, but the CONSPIRACY MANIPULATED THE FACTS!!11!"

Once a conspiracy is invoked, the argument is over, and the denialist has lost (Pal's Law?). A deus ex machina is the "nuclear option"---the validity of the argument is destroyed by rendering the premises unfalsifiable, unquestionable, and unassailable.

But rendering the premises immune from testing does not increase their veracity. In fact, it makes their veracity moot. Like any other argument, a conspiracy theory, and every other conversational machina have real, verifiable data to support it. My SciBling MarkH has often repeated, "Don't debate denialists" and I'm with him for the most part. The debate is useful when it hinges on facts. But once they role in the machine, it's time to pick up your toys and go home.

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Thanks for a nice post there. I posted an article based on peer reviewed research about the psychology of conspiracy theorists the other day which I think touches on this issue from a different direction.

In a nutshell, the author argued that there was a distinction between monological and dialogical argument. According to his view, dialogical argument engages with the context - the real world and evidence - while monological arguments are effectively closed, "ignoring their context in all but the shallowest respects". I'm not sure I fully agree with his distinction, but I do agree with his conclusions - that conspiracy theories act as a defense mechanism, allowing the person to prevent any new information from threatening their belief system.

What I'd really like to see is peer-reviewed research on the underlying causes and vectors of Denialism, and in particular how it can be isolated and tackled, both at the individual and social network levels. I'm tempted to do some research myself this autumn/winter when my current workload is reduced... I wonder if you guys have any ideas on this?

"Since the premises are invalid, the conclusions are false, despite a seemingly valid argument structure."

False. You can go from false or invalid premises to a true conclusion. It simply means the argument is not sound, and doesn't support the conclusion.

First, there seems to me to be two types of conspiracy beleivers: those seeking a superficial excuse for their situation and those who are deeply wounded and cannot muster the cognitive dissonance to bridge the gap between the assumptions they grew up with and accepted as undeniably true and their present situation.

The former tend to have grown up with few expectations or hope but they can't just come out and tell you they ended up where they were headed from the start. In deference to the social context that everyone has an equal chance and it is what you do with opportunity and effort that matters they act as if they believe it when, usually, they never have. This seems to me to be pretty common in poor communities. communities which have always known the deck was stacked against them. When they get the trope that they didn't try hard enough they can toss off a conspiracy theory to excuse their lack of standing. It is easier than bucking the assumptions about will and work and opportunity.

The other group are people who grew up inculcated in the idea that the world was your oyster. That anyone could be president. That all you had to do was show up, work hard and it would all work out. These are people who viscerally believe that they are in charge of their situation. They are often from lineages which saw an ever increasing standard of living. The expectation was that with every generation the children would be better off than their parents.

These are middle age folks, mostly white men, who are faced with a contradiction. They hold as sacred their belief in that capitalistic, free-market system that served their fathers. On the other hand they are seeing their economic and social situation deteriorate.

One one hand they believe that they are responsible for their situation. Believing otherwise in any way would be liberal and soft and contradict all they have felt about those they hold below them. The accepted formulation is that if your poor and lack power it is because of a character flaw.

On the other they know they have worked hard every waking hour. They have played the game diligently and honestly. But the results aren't showing up.

They know deep down the system works. They are working the system as hard as they can. They are falling behind.

Their assumptions and efforts can't be to blame. And the system can't be wrong. So ... there must be a nefarious external force at work. Obviously someone, probably liberal elites who never believed in the holy free-market system, is not playing by the rules. They have been conspired against.

It is a useful delusion. They don't need to question their beliefs. Or feel bad about blaming the poor for poverty. Even as they get closer to poverty themselves. They don't have to blame themselves for their deteriorating status or look for any character defects that might be holding them back.

Conspiracy is a lot of bang for the buck. A quick diversionary excuse for those who never had hope to use when faced with moralistic scolds. And a workable internal excuse system that eliminates any need to ask difficult questions or square expected outcomes with the experienced results.

Pal's law: Once a conspiracy is invoked, the argument is over, and the denialist has lost

this will be in my book now.

Really, this is a nice post. It points to one of the worst things that can happen to you when debating with crazys

Even if the premise about mercury in vaccines were true the conclusion would still not be valid. For example, fluorine is dangerous, toothpaste contains fluorine, toothpaste is not dangerous.

I realise this is OT, but you hit upon a massive pet peeve of mine when you misunderstood one of my favourite time travel special effects. So;

In the first Superman film, Superman does not reverse the earths rotation in order to turn back time. That is a stupid idea and, despite what a large number of people think they saw, that isnt what is portrayed on screen in that scene.

What happens is that the grief stricken Superman takes off and starts circling the earth. He accelerates until he is going faster than the speed of light (remember the red blur catching up with itself) and starts moving backwards in time. This movement back in time is represented to the audience as the earth slowing in its rotation and then reversing (as an external observer this isnt what the audience would normally perceive, however, I think it a more than acceptable piece of dramatic licence to show the earth as Superman would perceive it during that scene*). Once he has moved far enough back in time he slows down and returns to earth before Loise was killed and stops her getting caught in the earthquake.

You may consider this as a Deus ex machina, however, it isnt really a plot device, it is more a piece of character development, for the fist time Superman breaks one of Jor-Els rules (do not change earths history), to save someone he loves.

Now there are certainly a lot of real world physics issues with this scene, chiefly, as any physicist will confirm, the fact is that Supes can only travel faster than light when the Flash lends him access to the Speed Force. However, for all its flaws, it is nothing like as dumb as that Superman reversing the earths rotation notion (which I personally believe was started be a conspiracy led by Stan Lee, intended to make DC comic characters look like they dont understand physics).

*As he would perceive it if seeing anything whilst moving faster than the speed of light was a feasible concept.

I bow to your stunning Uber geek knowledge and understanding of the B-movies of yesteryear, the details of primitive special effects and the physics of their imaginary universe.

I touched on this in a previous comment a while back. There is a difference in knowledge and belief. We all use the wording that we "know" this or that, but the best we can hope for is to be justified in our belief. I would suggest that justification for belief has to be tempered by our education and intellect. Take two people presented with the same information. One is highly educated and highly intelligent. The other person is of average intelligence and education. The person of average ability may be justified in their belief even though they reach a different conclusion. Doesn't make them right, but it may give you more tolerance for dissenting thoughts, even though you "know" they are unjustified.

With that said, no premise can be beyond challenge. The more it is challenged and remains believed, the better the odds of it being right, but can it ever be 100% unquestionable?

(Sort of like Pal in that this isn't exactly where I was going with this when I started...)

My child will develop autism if they are vaccinated.
My child was vaccinated.
My child now has been diagnosed with autism.

Conclusion: The vaccine caused my child to be autistic.

I haven't spent any time looking at this argument. I tend to believe that vaccines are safe. But, I don't think you can totally, 100% discount the fears and concerns of parents that are questioning the safety of something that is going to be administered to their child.

(Now, fearmongering, scum sucking lawyers that try to stir up shit for their own profit, that's a 100% wrong, in my humble opinion...)

Well then, I accept your obsequience as no more than is fitting and forgive you for referring to a $55m film, with cutting-edge special effects, featuring great performances from Christopher Reeve, Marlon Brando and Gene Hackman (with the only half sensible super villain plan Ive ever heard of) as a B movie.

I forgive because thats what Superman would want me to do.

(Ever so) Slightly more on topic, mistaking what happened in that scene is exceptionally common, even among my fellow geeks.

Superman flies around the earth then the direction of rotation of the earth changes and people assume a basic causal relationship; that Superman changed the direction in which the earth spins.

Im pretty sure any comparison with a number of people in the Anti-vax movement doesnt need to be stressed.

In your example argument, one of the premises is not necessarily logically true. There are many humans that are still alive. Whether they are mortal or not is in a very real sense unknown. It is extremely likely, however extremely likely is an insufficient basis for logical truth.

94% of last year's flu vaccines contain Mercury
Other prescription drugs contain Mercury
Therefore, The USA is not mercury free.

Logical problems are always fun :>

I have really bad news for you, Chuck. The world will never be mercury-free.

The world will never be mercury-free.
Logical problems are always fun.
Therefore, we will have entertainment for years to come.

Bravo Alvaro! Bravo!

By Anonymous (not verified) on 12 Jun 2008 #permalink

Most vaccines no longer contain mercury.
The world will never be mercury-free.
Therefore vaccines will never be mercury-free.

I am having a little fun with this.

Roses are red,
Violets are blue,
Therefore, I hate coconuts.

Goatboy, Just saw Superman about six weeks ago. So, if the backward spinning Earth was just meant to represent Superman's going back in time, and not that he actually reversed the rotation of the earth, why did he then reverse himself, fly the other way several times around the earth, thus stopping the earth's backward spinning and starting it spinning forward again, all before heading back to Lois Lane?


Are you on the marketing team for Netflix?

By Anonymous (not verified) on 12 Jun 2008 #permalink

Anon, I don't get the reference...?

B follows A, therefore B is caused by A is not a justifiable belief. It may be an *understandable* belief, and it does not disprove that B *isn't* caused by A, but it is not justified.
As understandable as it is for a parent to want to protect their children, if they use non-justifiable information they may be tripped up by *justifiable* information.
For example: I am protecting my daughter from autism by not giving her an MMR vaccine. My daughter grows us, gets pregnant, and infected with rubella on a trip outside the US (only about half the countries in the world innoculate against rubella.) The developing fetus was miscarried (problems with developing fetuses are common when the mother is infected w/ rubella early in the pregnancy.)
Therefore, it is the fault of the drug companies that had a conspiracy against informing us of the dangers of vaccines. No, wait...

Mandrake, I agree. However, at what level of correlation do you go from understandable to justifiable? My point is, that level changes from one individual to another based on education (knowledge and/or familiarity with the subject at hand) and intellect (inate ability to understand the problem at hand). The better able you are to understand the premise, the more likely you are to reach the correct conclusion.

That doesn't mean that only the smartest X% of the population should be allowed to think. If you expect X to happen if you perform Y, then you perform Y and X happens, you are justified in thinking Y caused X UNLESS you have more information. What is understandable to one may be justifiable to another, based on their individual ability.

Think of any theory that was common knowledge at some point in history and was later disproved. It was justifiable until it became merely understandable.


This research is certainly being done. While the work is necessarily descriptive, there is excellent work being done on the psychology and epidemiology of conspiracism. start here.

I would say that most theories that were "common knowledge" were never justified, they were just assumed. (& assumptions frequently came from religion.)
I suppose that I'm using justified, among other things, to mean "logically consistent." Most people may not know formal logic, but they can usually understand causation, *except* when strong emotions are involved. Thus "understandable" rather than "justified."
Oh, foo. I have to go pick up my friend's rat at the vet (long story.) will try to get back to this later, it's been interesting.


Thanks for pointing that out. I've seen a few things like this around, but I still think there's a lack of analysis of hard data, even though potentially there is a vast amount of information on the web waiting to be mined.

I've actually got a rough hypothesis and methodology for one study figured out, but I'm not sure I want to give too much away here just yet. In a nut-shell though, it would involve mining the data I just mentioned to build network representations of a real conspiracy (BCCI, Enron), and a Conspiracy Theory (9/11, Mercury-Autism), with the rough hypothesis being that even if you ignore the falsehoods and logical fallacies, the resulting nets would look fundamentally different. That could have all sorts of practical applications then for future research, or for "diagnosing" theories.

It'll be a couple of months before I can really start getting to work on it, but tentatively, if anyone is interested, or perhaps even wants to collaborate on the research with the aim of getting a paper out (people familiar with network/complexity theory would be handy, as would people willing to trawl through and manually data mine websites to help create the dataset needed), maybe they can get in touch?

Mercury is toxic
Vaccines contain a little mercury
Coal-fired power plants distribute loads of mercury
Coal-fired electricity keeps my TV, cable, X-box, internet, microwave, hair dryer, and Christmas light display cheap

Therefore, make a big fuss over vaccines

I bring this up because the machina is also used in debates. A valid logical argument (OK, philosophers, please hold your horses...this is the 101 course) requires true premises and a conclusion that must follow.

Argh. :-|

Okay, I teach a 101 course on logic, so I feel an uncontrollable compulsion to respond to this.

On the very first day of class I spend a big chunk of the class time hammering into the students' heads that a valid argument does NOT require true premises. Truth and validity are two different things. For instance, the following argument is completely valid:

All dogs are birds.
John McCain is a dog.
Therefore, John McCain is a bird.

The fact that every statement in the argument is demonstrably false is irrelevant to whether the argument is valid, because validity has to do with the FORM of the argument, not its content. The above argument is valid, but since it contains a false premise, it is unsound.

Mercury is toxic

Vaccines contain mercury

Therefore, vaccines are toxic

This argument is a properly constructed, superficially valid syllogism. If the premises are true, the conclusion is true.

But the premises are not true. Mercury is toxic---sort of, some of the time, in certain forms, in certain doses, delivered in certain ways.

Most vaccines no longer contain mercury.

The argument about mercury you give as an example is actually an example of the Fallacy of Composition, an informal fallacy. Even if the premises were true, the conclusion would not follow. An example of why the argument doesn't work:

Stones can be hurled at people.
Bridges contain stone.
Therefore, bridges can be hurled at people.

So you don't even have to worry about the superficial validity of the argument. It can be refuted simply by pointing out that it is a fallacy of composition. Much of the anti-vax case consists of false cause and composition fallacies, and this is one of the biggest points against them.

Since the premises are invalid, the conclusions are false, despite a seemingly valid argument structure.

1.) Proving the premises false does NOT prove the conclusion false. It only proves that the conclusion does not follow from the premises (i.e. it shows that the conclusion has not been adequately demonstrated). To prove the conclusion false you need a separate argument demonstrating the negation of the conclusion to be true.

2.) Premises cannot be "invalid". Only whole arguments can be valid or invalid. Premises can be either true or false.

Sorry to be so pedantic. It's just a pet peeve of mine. I'll go back to being a friendly reader now. :)

D'oh! Irony alert. In lecturing PalMD on his logic, I made an pretty dumb error of my own.

The statement in the post above should read: "It only proves that the conclusion does not follow from TRUE premises", and it should have included a note that there might be other arguments with true premises from which the conclusion actually does follow.

Of course the conclusion still follows from "THE" false premises, but by showing the premises to be false you've shown that the conclusion has not been adequately demonstrated by the argument.

My bad.

Your comments, Wes, are always appreciated. I really never meant to get into formal logic, as I did not do very well in philosophy. Your comments have obviated the need for a rewrite. Thanks.

Stones can be hurled at people.
Two small stones across a stream is a bridge.
Therefore, bridges can be hurled at people.

Was the example that Wes (I believe) was refering to.

So prove either of these statements to be false:
Mercury is toxic
Vaccines contain mercury

and the conclusion that PAL set up:
Therefore, vaccines are toxic

will also be false.

I'm sure Wes will want to correct me since I only took the logic class and didn't teach it.

The conclusion is only false from a logical perspective, not a medical one and if V U M where
V = Vaccines that contains mercury and M = Mercury is toxic

So, Chuck, since vaccines do not contain mercury, and the MMR and OPV never did... there is no problem with vaccines.

Though in a reality, the dose makes the poison... you actually have to prove that the level of an ingredient (be it Hg, Na, Cl, C, N, or even H and O) causes a problem. Considering the death of a mother of small children California from water intoxication recently, you might argue that the sterile water used to reconstitute the MMR vaccine powder is toxic ( ).

But that would be very stupid.

Which is what this whole thread has shown... that there are those who take these simple logic limericks to stupid conclusions. In reality we need real data, and real information that includes the dose, the frequency and the relative risks from the vaccine and the actual disease.

Because which is really more dangerous: The MMR (which never contained thimerosal) or measles, mumps and rubella... or DTaP versus diphtheria, tetanus or pertussis (all three of those diseases create their own real toxins!), or Hib versus the real disease, or IPV versus polio..?

Really, where is the evidence?

The conclusion is only false from a logical perspective, not a medical one and if V U M where
V = Vaccines that contains mercury and M = Mercury is toxic

No, it's false, period. Here's an analogous example:
Hydrogen and oxygen are flammable.
Water is composed of hydrogen and oxygen.
Therefore water is flammable.

94% of flu vaccines, some adult vaccines, and other perscription medications still contain mercury so the statement "vaccines do not contain mercury" is false. MMR never has and I never stated that it did.

I also stated that I was having fun with this thread from the very begining.

Most pediatric vaccines do not contain mercury. Most children do not get the influenza vaccine. Even if you were having "fun" you still try to create a tempest in a teapot for no good reason.

I understand that you are very much affected by autism. I do empathize with you (since our son has a similar but different disability, but with the additional heart condition that would make him more vulnerable to the actual diseases). But there is absolutely no real evidence that vaccines, with or without thimerosal, have any connection to autism.

And even with the thimerosal in the adult influenza vaccine, my almost 20 year old son is better off getting the vaccine than the disease.

If you have evidence that the influenza vaccine (which is not perfect, and needs to be changed every year) is worse than the influenzas it is designed for... present that evidence. That same goes for other medications. Like the anticonvulsants he had as an infant when the seizures did not stop until he got them. Like the beta-blockers he takes, and the Tdap vaccine he had last fall.

Seriously, how are those meds more dangerous than the possibility of the "sudden death" that can occur with hypertrophic cardiomyopathy with obstruction?

"If you have evidence that the influenza vaccine (which is not perfect, and needs to be changed every year) is worse than the influenzas it is designed for... present that evidence."

Last's years influenza was 40% effective. Those 60% that did get vaccinated were given false hope and assurance, wasted both time and money in getting the vaccine and for treatment for influenza.

By Anonymous (not verified) on 16 Jun 2008 #permalink

Keeps posting Anon Grrr

Oh and some of those 60% probably died also.

Of those 60%, they probably also waited until it was too late to minimize any further health problems because they thought it was just a cold and couldn't be the flu because they got the vaccine.

As Paris plucked by the gods from the blade of Achilles, so too the mind of the antivaccinationist is plucked from the truth...

(only did a year in classics, but I loved it)