Steelman
Circumstantial ad hominem
Also called appeal to motive, vested-interest fallacy, bulverism.
Dismissing an argument because of the arguer’s circumstances or motives.
What it is
Rejecting someone’s argument by pointing out that they have something to gain, or are in circumstances that incline them toward that view, instead of showing what’s wrong with the argument.
The pattern
A argues X. A would benefit if X were accepted (or A’s situation predisposes them to X). Therefore X is false.
An example
“Of course the teachers’ union says smaller classes improve learning. They just want more teachers hired.”
The union’s interest is a reason to look hard at its evidence, but the research on class size stands or falls on its own.
Why it fails
A motive to argue for something is a reason to check the argument carefully, not a reason to think it’s wrong. People with a stake in an issue can still be right, and their arguments can be evaluated like anyone else’s.
When it’s not a fallacy
Most lists skip this part. Calling a fair point a fallacy is a mistake too.
It can be fair when
- The argument depends on the person’s own testimony or judgment rather than checkable evidence. Then their incentives bear directly on how much to trust them.
- You’re deciding how much scrutiny to apply, not dismissing the conclusion.
Try one
A question from the app. The wrong answers are its usual look-alikes.
Town hall. Diner owner: “I pay $14 an hour now. At $20, my payroll goes up about $90,000 a year, and the diner clears maybe $60,000. I’d have to cut staff or close.” Organizer: “With respect, you’re the one who’d be paying it. Of course the numbers look scary from your side of the counter.” Moderator: “Thanks. Next up, the school bus routes.”
What’s the flaw?
The owner’s stake is a reason to check his numbers, not to wave them off. Payroll and profit can be checked, and the organizer answers none of it.
A fair reply
“Then check my books, and if the numbers are off, show me where.”
Often confused with
- Genetic fallacy
The genetic fallacy targets where an idea came from. Circumstantial ad hominem targets why this person holds it.
- Poisoning the well
Poisoning the well discredits someone before they speak. Circumstantial ad hominem dismisses an argument already made.
Where the name comes from
“Ad hominem” is Latin for “to the person”, and “circumstantial” aims it at the person’s situation: their job, their paycheck, their side. “Appeal to motive” and “vested-interest fallacy” name the usual target: what they stand to gain. Bulverism is named for Ezekiel Bulver, a character C. S. Lewis made up. At 5, he heard his mother answer his father with “you say that because you are a man” and decided proving people wrong is optional.
C. S. Lewis coined “Bulverism” in a 1941 essay for the habit of explaining why an opponent came to be wrong before showing that they are wrong. He named it after an imaginary inventor, Ezekiel Bulver.
Sources
- Fallacies, Bradley Dowden, Internet Encyclopedia of Philosophy
- Ad hominem, Wikipedia
In the app
Practice spotting it on arguments that sound real.
Steelman has more examples of circumstantial ad hominem, how to answer it in a real conversation, and practice rounds that mix it with its look-alikes, so you learn the difference, not just the name. Coming soon to iPhone and Android.
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