Skip to content
February 23, 2009 | 25 Comments

What appeal to authority means and what it doesn’t

This article is meant to be the first is a small series of demonstrations of how not and how to argue for or against climate activism. The level of argumentation on the web has long passed subbasement (people have been calling each other “Hitler” for over two years), but worse are the misuses and misunderstandings of logic. People throw around terms like ad hominem and appeal to authority constantly, without understanding what they are saying.

My hope is that when you see an abuse of the type outlined, you simply cut and paste the link to these pages. This will save us all a lot of time and unnecessary typing. I hope.


A prominent climate inactivist forwarded me a document in which he argued against some of the more catastrophic claims said to be due to global warming.

At the beginning of his piece he implied that James Hansen, who is the best known climate activist, should not be trusted because Hansen only had training as an astrophysicist and not as a climatologist.

This is a poor argument because the author of the piece was not himself a climatologist. If you must be an official climatologist before being allowed to comment on climatology—a position that is logically valid given that you can satisfactorily define “climatologist”—then just about everybody, activist and inactivist, must shut up. Including the author of that piece—and almost certainly, including you.


Mr Activist: this means that you would not be allowed to say anything whatsoever about global warming except to repeat what you have been told by an official climatologist. You would be allowed to say “Mr Climatologist says B” and nothing else.

(“B” can be any statement or proposition about climatology only—it cannot be about politics or health or biology or anything else.)

Mr Activist would not be allowed to say “Mr Climatologist says B, and you’re a fool not to believe it.” Pause and understand this. The reason is that he is not qualified to say what and what is not foolish because he is not a climatologist.

If an official climatologist says “B, and people would be fools not to believe it,” then you can repeat that statement. But you cannot adorn it, nor comment further, nor say anything else. You can repeat what you are told by your betters and then you must keep quiet.

The only exception to this logical rule is that if everybody, activist and inactivist, agreed on the additional premise, “People that do not believe what official climatologists say are fools.” Then you can logically say, “Mr Climatologist says B, and you’re a fool not to believe it.”

But almost certainly, everybody would not agree on that premise. Let’s see why.


The prominent inactivist made a logical mistake by arguing “Because Hansen is not a climatologist, his statements on climatology are false.” This is only valid if only climatologists make true statements about climatology and if non-climatologists always make false statements about climatology. Is that true?

Obviously not. Plenty of climatologists have made statements about climatology that turned out false in fact and in theory. And plenty of non-climatologists have made statements about climatology that turned out true in fact and in theory.

Because of this, it necessarily means that anybody is allowed to say anything they want about statements of fact or theory about climatology. This includes both activists and inactivists. We can now see that neither side can accuse the other of making a logical mistake by talking about climatology.

So stop arguing about this point!


Suppose Hansen is an official climatologist and he makes the statement, H = “The global average temperature in 2010 will be at least half a degree hotter than in 2009.” (Whenever we see ‘H’, we must remember that it stands for “The global average…”)

If an activist then says, “Hansen, an expert, says H. Therefore, because Hansen is an expert, H is true.” This argument is invalid; the activist has made a mistake. H cannot be true because Hansen said so. The logical error made is called “appealing to authority.”

Most know of this mistake and avoid obvious instances of it. But see 5.

Suppose a second activist said, “Hansen, an expert, says H. Therefore, because Hansen is an expert, H is likely to be true.” This is not a mistake and is a rational thing to say. This is because experts making statements like H are often, but not always, right. Therefore it is rational to suppose that the expert is likely to be right again.

The statement made by the second activist is an appeal to authority, too, but a sound, inductive one.

Mr Inactivist: it does you no credit to accuse non-climatologists of being irrational if they are making arguments of the second type. It is often wise to appeal to authority like this, and is what we all do when we enter an aircraft, trusting the pilot to get us safely to our destination.


Most will agree that Hansen meets the definition of climatologist, but then so does your author, and so do several people (like Dr Lindzen) who do not always agree with what Hansen says.

Now we have trouble. For if only official climatologists can make true statements about climatology, and if two (or more) official climatologists make contradictory statements about climatology, then we have a logical contradiction if the premise “Only climatologists make true statements about climatology” is true. We have already seen it is false, so we are safe.

But suppose Mr Activist says, “Most climatologists say B. Therefore B is true.” This is the same logical error: appeal to authority in the deductive sense.

Let the second activist say “Most climatologists say B. Therefore B is likely to be true.” This is a perfectly rational thing to say.

Even more, the first premise appears to be true in fact: Most climatologists do agree on most statements B about climatology. Therefore, it is rational for people, and their close cousins politicians, to say to themselves “B is likely to be true.”

Mr Inactivist: your only appeal, if you believe B to be false, is to marshal arguments against B. You must not call B a “hoax” or use other disparaging terms as you risk being guilty of appealing strictly to your own authorities (however, there is more to say here, but we’ll save this for another time).

Mr Activist: Because you have reasoned B is more likely to be true, you cannot say “Therefore, everybody must believe B.” To do so is to make the same appeal-to-authority logical error. You must also not express amazement that anybody dare disagree with B for the same reason, and because you must remember that the inactivist has consulted his own authority or set of facts and is arguing inductively just as you are.


Mr Activist, you must not say that Mr Inactivist’s authorities are ineligible because they do not agree with your authorities. This is the same logical error: appeal to authority once more.

And it is a foolish thing to say because you risk defining “expert” solely as “somebody who agrees with what I want.” That is not a logical error, but it is asinine.


Finally, Mr Activist, you must understand Mr Inactivist is making an inductive, and therefore rational, appeal to authority, when he argues “Yes, most climatologists say B, but I believe they are mistaken because these other climatologists claim to have shown where the first are in error.”

Thus, if Mr Inactivist says, “Therefore, B is likely to be false”, then he has said a rational thing. But if he has said, “Therefore, B is certainly false”, then he has made the same error and you can call him on it.


Update: I want to leave as an exercise about how arguments about “peer review” and “consensus” fit into the appeal to authority arguments. After you have said something about “peer review”, then read this article.


Just upgraded. Anything unusual?

Joy noticed that my older version of WordPress was once again hacked to insert a list of drug names into the theme header.php file.

So, I upgraded. When I did, I noticed 24 comments that were made over a long course of time, all marked as Spam, but all not. Some of these were duplicates that I removed, and I approved the rest. I have no idea where these came from, because I could not see them before. Strange.

Took a look at the theme, which looks the same, but if anybody notices anything weird, please let me know by comments here, or by email at

Thanks, all.

February 20, 2009 | 3 Comments

Today’s groaner

How many bishops does it take to celebrate Earth Hour?


(….pause for laughter….)

Those wrestling guys at the WWF have been sending me emails touting earth hour again.

Spokesman Dan Forman says they’re pretty happy to have enlisted Bishop Desmond Tutu who, presumably along with Hulk Hogan, “Stone Cold” Steve Austin, and some of those other steroidal creations, will switch off their lights for an hour, starting at 8:30 pm on Saturday March 28.

This is to make the Earth happy.

I’ll be with them. My lights will be out as I listen to the Vicar of Vintage Vinyl, Danny Stiles, whose show is on every Saturday night. 820 AM in New York City.

Go Earth!


You’re welcome

Dear Mortgage Holder,

Obama’s latest plan must sound pretty sweet to you. You bought a house and paid too much for it.

It didn’t look that way at first because after you bought the house, it went up in value. Prices were rising everywhere fast. Reasoning that nothing could go wrong, you took out a home equity loan on the increased value so you could get that flat screen TV and some other things you “needed.” You really ran up those credit cards.

But then the housing prices started falling to more realistic levels. Sure, they fell fast and some of that decline was caused by idiot bankers making risky loans to people…like you, maybe?

Now your mortgage payments are killing you and you’re complaining about it.

Obama has heard your cries. He has decided to dig into the treasury and give money to lenders so that you can refinance your house and lower your payment.

You remember that I have been renting. I’ve been saving my money, keeping my bills low, scrimping and acting responsibly. When you made your loan, remember how I laughed at you and said you were being foolish? “How can you expect to pay for all that extravagance?” I asked. Boy, was I smug and morally superior.

But you got the last laugh. Because I saved and did well, my taxes are going to go up, so that Obama can pay the bill for all this refinancing.

In effect, the money that I have been saving to buy my own house will be going to pay for yours.

I read in the papers that a lot of “journalists” and politicians think this is “fair.” They want to move quickly, too, because they think if we don’t then the economy will get worse. How do they know? They don’t. It’s just a guess. But everybody will be happy because the government is giving away money. They never stop to ask where the money comes from.

You’re probably so happy that you hadn’t even thought of the best part. See, your payments will go down and you get to keep your house. That part you knew. But your house will also increase in value in a couple of years. That means you’ll be able to sell it at a profit. So you’re getting a kind of double gift; you’re going to be doing pretty well after all.

All thanks to me and my money.

Just wanted to say you’re welcome.

Your Pal,