Appeal to authority is a fallacy that relies on the opinion of an authority figure instead of evidence. The authority might be an expert. The authority might be a celebrity. The fallacy occurs when the authority is not an expert in the relevant field, or when the authority's opinion is treated as proof. Experts can be wrong. Experts disagree. The appeal to authority avoids the evidence.

The fallacy is common in advertising. A famous athlete endorses a breakfast cereal. The athlete knows nothing about nutrition. The endorsement is irrelevant. The fallacy is also common in politics. A respected general supports a tax policy. The general knows about military strategy, not economics. The support is irrelevant.

Appeal to authority examples

• This doctor says the supplement works, so it must.
• Einstein believed in God, so God exists.
• The president supports the war, so it must be just.
• A Nobel laureate endorses this economic theory.
• My teacher says this is true, so it is.

Appeal to authority is not always fallacious. Sometimes authority is relevant. A cardiologist's opinion on heart disease carries weight. A climatologist's opinion on climate change carries weight. The fallacy occurs when the authority is irrelevant or when the appeal replaces evidence. The proper use of authority is as a guide, not a proof. An expert's opinion is evidence, but it is not conclusive. Other experts might disagree. The evidence might point the other way. The appeal to authority becomes a fallacy when it shuts down inquiry. The authority is a shortcut. Sometimes shortcuts are useful. Sometimes they lead you off a cliff.