Websites with an agenda to promote will claim that someone has “refuted” a claim when all the person has done is express a contrary view, with or without supporting evidence.

Refuting a claim or argument means showing that it’s invalid. It doesn’t require proving that the contrary position is true, but it requires thoroughly knocking the props out from under a claim. Here are some ways to refute an assertion:

• Showing that the assertion depends on a logical fallacy. Example: The person making the assertion treats “X happened after Y” as “Y caused X” without giving any evidence of causation.
• Relying on clearly untrustworthy sources. Example: The source for a factual claim is a website with a long record of lies.
• Presenting conclusive evidence to the contrary. Example: An allegedly dead person makes a public appearance. I once did that myself.

The following don’t count as refutations:

• Statements by an “expert” that the claim is false, without supporting arguments.
• Expressions of outrage and ridicule.
• Attacks on the character of the person making the assertion. (Showing that the person’s record on factual claims is poor, when there’s no independent support for the assertion, is a different matter and doesn’t count as ad hominem.)

Some counter-arguments cast doubt on a position but fall short of a refutation. Many issues are legitimate areas for debate, with neither side being able to refute the other quickly. Even highly regarded experts are sometimes wrong.

Writers, please don’t try to close off debate by claiming someone has delivered a knock-down refutation of a claim when there’s still room for doubt.