The Circular Reasoning Fallacy and Gizmo's Super Potion

Will Bruno be a part of this brutish experiment?

Bruno is too clever for Gizmo's trickery. He knows the elixir isn't safe, and that Gizmo clearly has nothing to back up his claim.

See through those who speak in circles with our Circular Reasoning Activity Pack.

Circular Reasoning in a Nutshell

"It's safe because it works. And it works because it's safe."

Gizmo has just gone in a perfect circle. He hasn't proven the potion is safe - he's just restated the claim twice in opposite order and hoped nobody would notice. That's Circular Reasoning, also known as Begging the Question (petitio principii): using your conclusion as one of your premises. The argument looks like it's moving forward, but it's actually standing perfectly still.

Bruno spotted it immediately. There's no evidence here. No data, no testing, no reasoning that doesn't start and end at the same place. Just Bubba - enormous, drooling, somewhat alarming - presented as proof that everything is fine.

The fact that something appears to work isn't evidence that it's safe. And the fact that it's claimed to be safe isn't evidence that it works. Bruno was right to stay put.

See all 24 fallacies in What Are the Most Common Logical Fallacies?

If you would like to receive our weekly comics, plus regular fun freebies, updates and more, sign up to our weekly newsletter. Scroll down to subscribe.