Exposing PseudoAstronomy

November 13, 2009

Logical Fallacies: Ad Hominem Attacks and the Sub-Types of Tu Quoque and Poisoning the Well


In my third installment of my series on Logical Fallacies, we’re going to cover the “ad hominem” attack along with several sub-types.

What’s an Ad hominem?

Ad hominem is a Latin phrase that literally translates as, “to the person” (and because it is in a language other than English, when using it in an English sentence it should be italicized). This is apropos because the fallacy is when one attacks a person making claims rather than the claims themselves — in other words, they address their arguments “to the person” rather than the claims. Because this is a fairly general fallacy, there are several sub-types.

Example of the Ad hominem, Abusive

There is no real standard ad hominem that I could think of in terms of creationism, intelligent design, UFOs, 2012 doomsday people, Planet Xers, astrologers, and all the rest of the pseudosciences that I’ve addressed on this blog. Really, the ad hominem is usually a spur-of-the-moment type of fallacy and generally used when one is just plain annoyed and wishes to use malice.

A contrived example would be the following situation: A die-hard UFO=aliens believer is debating with the virtuous skeptic when, frustrated, the UFO believer cries out, “Well of course you don’t believe me, you just believe whatever those scientists tell you to believe.”

Now, of course, this can easily go both ways. For example: A skeptic walking down the street sees a sign for a Psychic / Palm Reader / Tarot Card Reader / Astrologer, sees someone walk in, and obnoxiously declares, “Yeah, you’re gonna trust her — she doesn’t even have a real job!” The skeptic has just addressed the person rather than the actual claims.

Example of the Ad hominem, Circumstantial

This variety of ad hominem, rather than direct character assassination, uses circumstances rather than the person. For example, to pick on the Noble Skeptic, a skeptic might claim of a seriologist (someone who studies crop circles), “Well of course they believe crop circles are caused by aliens. That’s because they run a tour company and charge lots of money to bring people to see the formations.”

Assuming the seriologist in question actually does this, then the skeptic has just used the circumstantial ad hominem where they have drawn an albeit valid link that may be some of the seriologist’s motivation, it still does not address the actual claims of crop circle believers.

Sub-Type: Tu quoque

Lots of Latin in this blog post! Tu quoque literally translates as, “You, too.” This form of ad hominem attack, rather than being used initially, often follows one lobbied against its user. It’s really the quite childish playground taunt of, “Oh yeah! Well so do you!”

To continue my above example of the seriologist, once the Noble Skeptic has used such a logically fallacious circumstantial ad hominem, the seriologist may come right back with, “But you charge admissions to your lectures against aliens, crop circles, and UFOs!” In other words, they’ve just pointed out that the very ad hominem used against them – financial ties to the cherished belief – can also apply to the skeptic.

But again, the actual claim itself of whether crop circles are caused by aliens has not been addressed.

Sub-Type: Poisoning the Well

“Poisoning the Well” is a sub-type of ad hominem where, rather than outright attacks on a person or group, the attack is subtle and tries to get the listeners to distrust the person or group being attacked. They have been, effectively, “poisoned.”

An example of this that is often used by both creationists but much more so by the Intelligent Design proponents is calling pretty much anyone who disagrees with them a “Darwinist,” “Evolutionist,” or even “Evilutionist.” In other words, without addressing any of the claims themselves, they have already biased their audience against those people by giving them a seemingly unfavorable characteristic.

The Inverse ad hominem

I’ll address this more in my upcoming post on the Argument from Authority as a sub-sub-sub-…-sub type of that, but suffice to say here that the inverse ad hominem is just what it would seem to be. But rather than used to argue against someone or something, it’s used to try to give undue support for their position.

For example: “That Creationist on-stage is much better dressed than his opponent. He must really know what he’s doing to show up like that.”

Or, in every-day life, when walking down the street people will usually give much more sidewalk space to someone dressed in a tuxedo, evening gown, or priestly garb than a person walking in sweat pants and a t-shirt.

Final Thoughts

Everyone uses ad hominem attacks. I’ve used them, you’ve used them, we’ve all used them. But, it’s an argument ad populum (again, future post!) to say that because everyone uses them, they’re a good way of arguing. They’re so often used in politics that most people have turned away from politicians and created the joke of “politicks = poly + ticks, or “many” + “blood-sucking insects.” Of course this, in itself, is an ad hominem.

I should note, by the way, that something is only an ad hominem IF it is used as an argument in itself. Just using it in an argument or on the school playground to call someone a “jerk” for example is NOT an ad hominem. However, the poisoning the well fallacy is not as subject to this restriction.

And before some commenter points it out, I used ad hominems and inverse ad hominems throughout this post, such as the “Noble Skeptic” or “die-hard UFO=aliens believer.” Yes, I know I used them. I did it on purpose. Thank you for not using your own tu quoque in the Comments section.



  1. An astro example of “poisoning the well” might be found in Joe Rogan’s moon denial debate. The moon shot was run by former Nazis. And UFO skeptics are accused of being on the NASA payroll.

    Comment by Karl — November 13, 2009 @ 10:54 am | Reply

  2. the aliens wont let us be illogic

    Comment by Thank You! — November 23, 2009 @ 6:27 am | Reply

  3. Tu quoque, I think, can have a use. For example, a naturopath claims a profit motive necessarily leads meidcal doctors to make judgments about a person’s health. The implication is naturopaths don’t and therefore they necessarily arrive at treatments in the best interest of the patient. However, naturopaths don’t give their services away for free, and unlike doctors who don’t dispense, naturopaths will sell you potions with alarmingly high price tags. Pointing out “you did it too” elucidates the fact either profit doesn’t not always lead to compromised health care or the naturopath also cannot escape that profit clouds judgment and the patient needs to be as skeptical of the naturopath as he is of the doctor. Otherwise, one then commits the inconsistency fallacy.

    Comment by Karl — December 3, 2009 @ 9:41 am | Reply

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