Circular reasoning

Circular Sally

“I'm right because I'm correct.”

What's the problem?

Circular reasoning (begging the question) offers as support something that already presupposes the conclusion, so the reason gives no grounds that a doubter could accept without first accepting the claim. Sometimes the conclusion is restated in other words; sometimes it hides in a premise, or two claims prop each other up. Not everything that looks repetitive is circular. A definition explains what a term means and isn't offered as evidence. A conditional argument can explore what follows from an assumption without claiming to prove that assumption, though labeling an assumption doesn't by itself make an argument noncircular. Independent support means the support doesn't already presuppose the conclusion; it needn't come from an outside organization. Keep source quality separate from logical dependence: an interested source's claim can be weak or biased without being circular. The test: could someone who doubts the conclusion accept the reason without already accepting the conclusion? Sally asks whether the support depends on the claim itself; Red-Herring Hank asks whether a response addresses the issue at all.

Context: A manager claims a new hire is trustworthy and supports it with the reasoning below. Two former supervisors have also provided references.

✗ Assumes its conclusion

We can believe her statement that she's honest because she's trustworthy; we know she's trustworthy because she says she's honest.

✓ Support assessed

Her statement can't vouch for itself. The two supervisors' references are additional evidence we can assess, though they aren't guaranteed to be reliable or decisive.

Why it works

Each claim in the original is supported only by the other, so the circle gives no independent grounds. The revision points to support that doesn't presuppose the conclusion, without claiming it settles the question.