A field guide to the ways reasoning breaks
Attacks on the source
Also called Fallacy of origins
Judging a claim by where it came from rather than what it says.
That idea came from a marketing team, so it is worthless.
Ask whether the origin changes the evidence. A good idea from a bad source is still good.
Named for 'genesis' — origin. The Oxford Companion to Philosophy traces the term to Morris Raphael Cohen and Ernest Nagel's 1934 textbook 'An Introduction to Logic and Scientific Method', which warned against confusing how a belief arose with whether it is true.
A manager dismisses a cost-saving proposal at review because 'it started as an intern's side project,' without opening the numbers.
A reader rejects a documentary's findings on factory farming because the production company also makes entertainment shows.
During a school board meeting, a parent objects to a new math curriculum on the grounds that its authors once worked for a testing company — and the objection is treated as a verdict.
A patient dismisses a diet guideline solely because an early version of it was promoted by a cereal company decades ago.