What it is
Assuming in the premises the very thing the argument is supposed to establish.
In the wild
The rules are correct because the rulebook says so.
How to answer it
Ask for a reason that does not already presuppose the conclusion.
Broken structure
Circular reasoning
Also called Begging the question, petitio principii
In depth
Origin and naming
Aristotle discussed it in the Topics and Prior Analytics as τὸ ἐξ ἀρχῆς αἰτεῖν — 'asking for the initial thing' — a fault in formal debate where one side requests the very thesis at issue. Latin translators rendered it petitio principii, and sixteenth-century English gave us 'begging the question'.
More places it shows up
This framework is the industry standard because it's the one the industry uses.
The new policy is fair because it treats everything in line with the policy.
You can trust the report — it was approved by the team that wrote it.
This diet works because it produces weight loss, and we know it produces weight loss because it works.
How to spot it
- Notice when stripping the wording down leaves the premise and the conclusion saying the same sentence twice.
- Notice when the proof works only for people who already agree with the conclusion.
- Notice when asking 'and why is the premise true?' sends you straight back to the conclusion.