Tuesday, October 12, 2010

Very informal fallacies

Logic students sometimes misremember or misspell the names of fallacies. One danger this poses is that it can inspire bored logic teachers to take a break from grading exams and write up ill-considered “humor” pieces. And so, in this blog’s proud tradition of rollicking comedy, here are some fallacies you’ve never heard of (though I bet you’ve committed a few of ‘em):

Post doc, ergo propter doc: The delusion that a Ph.D. confers wisdom, or even basic competence. Example: “Of course the medievals thought the earth was flat. It says so in the book! Who’s the professor here, anyway?”

Red hair-ing: Believing that something is true simply because a really hot redhead said it. Example: “Omigosh, Christina Hendricks is so hot. I would totally believe anything she says.”

Appeal to minority: The smug presumption that popular opinion, tradition, and plain common sense are always likely to be wrong. Often committed in conjunction with the Post doc fallacy. Example: “Of course, this goes against everything your parents, your pastor, and pretty much everyone else have always believed. So it must be true!”

Question the begging: Knee-jerk tendency to think that panhandlers, hard-up relatives, government employees, etc. are only going to blow any money you give them on booze and cigarettes. Not really a fallacy at all. Example: “I don’t care if he’s a legless veteran with five children and rickets! Didn’t you see that iPod?”

Democratic fallacy: Being a member of the Democratic Party and/or voting for Democratic Party candidates. Example: “I intend to vote Democrat this year.”

Affirming the consequences: Assuming that consequences are all that matter in morality. Also known as “consequentialism,” and often mistaken for an actual moral theory. Example: Pick any random sentence from a Peter Singer book.

Ad Eminem: Paranoid suspicion among some readers of right-wing blogs that absolutely everything about modern culture leads inexorably to rap music, pornography, and women wearing slacks. Example: “Did you read Feser’s blog post defending jazz?! Next he’ll be linking to YouTube clips from The Marshall Mathers LP!”


  1. This is what I will miss, now that I am banishing myself from this blog, for having been unanimously convicted of trolling on the previous post.
    Prof. Feser, at least teach the future philosophers to retain their humanity, even as they become more and more mere adjuncts to Latin dictionaries. We need this more today than ever. You rock.

    (PS. Eminem is a modern prophet. This, alas, is what a prophet looks like today.)

  2. Then there's productio ad absurdam: the notion that if the doctrine you espouse leads to absurd or unthinkable consequences, why then it is far more likely to be credible - or cool, at any rate.

  3. Kristor:

    Very clever. I'm assuming Peter Singer also works in this instance?

    There is also, of course, the real naturalistic fallacy, as well.

  4. Great post, as usual.

    I know this is off topic, but have you seen Jerry Coyne's latest piece on the incompatibility of religion and science (see Siris)? I'd be curious to know what you think of it.

  5. I'd be ok with the "red-hairing." That chick could probably talk me into just about anything.

  6. I know this is off topic, but have you seen Jerry Coyne's latest piece on the incompatibility of religion and science (see Siris)? I'd be curious to know what you think of it.

    One bit of oddness to keep in mind about Coyne is that for all his bluster, he also has repeatedly stated that belief in the existence of God is entirely compatible with science. But, he says, this God must be an entirely Deistic God - no intervention in the universe, no plan for it, nothing. Even starting up the universe and letting it unfold according to a plan is disallowed, if I recall him right.

    That, to me, is a pretty incredible position to hold.

  7. The Red Hairing fallacy should be a species of a larger category to describe the spate of cute, young and clever women, fast-tracked to the top of their respective careers that have cropped up in recent years to include examples like Naomi Klein and her thesis that brutal dictators are just fine as long as they are not for free trade. Or journalist Ann Curry who asked Rick Warren if he would change his mind about homosexual acts if it were proved that people were born with that desire. He replied that no he wouldn't because just as he was born with a desire to have sex with every beautiful woman he saw, it doesn't make it right. She had a look like a gorilla asked to do vector calculus. Or Maureen Dowd, who...err...scratch the young part and frankly the best response to anything she says is "Catherine Zeta-Jones Douglas".

    Scott W.

  8. The "appeal to minority" fallacy is real and it comes right out of the naturalist's playbook. How many times have we been told that some bizarre, counterintuitive "explanation" of the mind is rationally obligatory because it comports with what "science" says? And, of course, it is simply presumed that "science" invariably conflicts with common-sense and with popular opinion. Daniel Dennett is a leading proponent of this strategy. In his recent book _Sweet Dreams_ he diagnoses the belief in geocentrism as the result of "common sense" and proceeds to argue that dualistic "intuitions" are on the same epistemic footing. Where do you even begin with such rank confusions and historical ignorance? And, sadly, these sorts of claims are rhetorically quite effective.

  9. I'm not sure this is a logical fallacy, but looks like it fits: the "loved lapdog" fallacy. The fallacy that if you spout often enough and loudly enough exactly what you have been told to spout in school, your professors / teachers / leaders / will love you for it and respect your intellect. They may well pamper you, but this is of course done while they quietly maneuver a pillow over your head to smother you when you become sick or disabled or old.

  10. I'm with Josh on the Red hair-ring.

    Who cares if it's a fallacy! (And I'm sure female bloggers are just as prone to this fallacy! My wife insists that Christian Bale is intelligent and sensitive. This was before she examined the evidence, and after she examined evidence to the contrary!)

    Naomi Klein? Hot? I have to contest that claim!

  11. You know - the "question the begging" paragraph manage to be insanely left and right wing - at the same time!

    Usually you have to be European to manage that!

  12. Sinai qua non

    The belief by militant theists that faith -- specifically Judeo-Christian faith -- is indispensable for morality.

  13. Red hair-ing: Believing that something is true simply because a really hot redhead said it. Example: “Omigosh, Christina Hendricks is so hot. I would totally believe anything she says.”

    My very weak contribution is the False Dye Lemma - a subsiduary proposition which holds that it's so not the same if the colour's fake.

  14. I'm a little surprised that no one has mentioned the ad homonym attack, which is one that sounds like something that made sense before...

  15. Naomi Klein? Hot?

    Didn't say hot.

  16. There's always the political Left's favorite, i.e. the fallacy of the undistributed middle class, i.e. the presumption that if X is a Republican policy, then X must be aimed at making the rich much richer, the poor much poorer, and the middle class non-existent.

  17. This comment has been removed by the author.

  18. reducto ad nomen

    The fallacy where one claims to have defeated your argument, simply by naming the "school of thought" from whence it was first devised.

  19. romishg

    I'm glad that we agree on an essential point. If the "red hairring" worked for Naomi Klein, all rational dialogue would break down and civilization would collapse.

    Mind you, it seems to work for George Clooney and Matt Damon...so half of western civilization has fallen to the fallacy...

    If they can bring Christina Hendricks on board, it could be over for the West!


  20. Although I note that you call Naomi Klein "cute"

    Shurely shome mishtake?

  21. what about the fallacy of "ad infant-itum"? claiming support for an idea because "even a child knows it". forgetting the fact that these same children eat their boogers.