Confidence is not evidence

The most persuasive people are often the most certain, and certainty is not connected to being right. Someone who has never checked can sound completely sure; someone who has checked carefully often says *it depends*.

This matters because we mostly judge claims by delivery. A confident voice, a confident face, a confident number. None of those is evidence, and all of them are easy to produce.

Three questions handle most claims:

What exactly is being claimed? Vague claims cannot be checked, which is often the point. *"This course changes lives"* says nothing testable. *"Most graduates find work within six months"* can be checked, and that is why the first kind is more common in advertising.

How would they know? Did they measure it, or is it an impression? Did they count, or estimate? A claim about thousands of people made by someone who has met twelve is an impression wearing a statistic's clothes.

Who benefits if I believe it? Not an accusation. A seller can be honest. But knowing who gains tells you where to look hardest.

The hardest part is applying this to things you already agree with. Everyone is sceptical of claims they dislike. Critical thinking is the same scrutiny applied to the claim that flatters you, and that is where it is actually difficult.

Being unsure is a legitimate position. *"I don't know enough to say"* is a real answer and usually a better one than a confident guess. The pressure to have an opinion on everything produces a great deal of nonsense.