a field guide to fallacies

No. 09 Appeals to Authority and the Crowd argumentum ad verecundiam

Appeal to Authority

In Turkish: Bir Bilen Safsatası

“Someone who knows said so.” Who, knows what, and how?

My cousin in Germany says buy this one. German cars never break down.

A man who lives in Germany would know! It’ll never break!

The cousin’s a barber, Temel. Ask a mechanic about the car.

What is it?

Accepting a claim because the person making it is important or familiar. Expertise counts in one field; fame counts in none; and “living in Germany” counts only on the subject of Germany.

The pattern

  1. Person A says X.
  2. A is important / famous / educated / lives abroad.
  3. Therefore X is true.

Why it fails

We have to trust experts; nobody can measure everything themselves. The trouble is trust carried to the wrong place: the cardiologist’s car advice, the footballer’s toothpaste, the cousin’s repair knowledge. And the real question: whatever the expert said, is there evidence for it? What makes an expert is being able to show the evidence, not the title.

How to spot it

  • There’s a name or a title where the evidence should be.
  • The title doesn’t match the topic: a doctor on cars, a mechanic on diets, an expat on everything.
  • Ask “why?” and the answer is “because they said so.”

What to say

“And what did they base that on?” A real expert has the evidence and can explain it. If they can’t, you’ve got a name, not a claim. Then ask about the field: “Is this actually their subject?”

When it’s not a fallacy

Trusting a genuine expert on a subject inside their field isn’t a fallacy; it’s sense. The cardiologist on hearts, the mechanic on cars: that’s a solid reason, not final proof, but a good start. The fallacy is carrying the title outside its field, or putting the title where the evidence should be.

Examples

  • AdsA famous actor praises a bank’s interest rate. Actors know acting, not interest.
  • Health“Our neighbour the doctor says this diet works for everyone.” Which doctor, which specialty, which study?
  • Tech“My nephew works in computers, he says this phone is bugged.” The nephew builds websites.
  • School“The teacher said so.” One teacher; a thousand people wrote the book.

Don’t confuse with

Sources: IEP, Fallacies: Appeal to Authority · Douglas Walton, Appeal to Expert Opinion (1997)