Lesson · 4 min Gentle
A Weak Analogy
In one line A good analogy shares the feature the conclusion needs; a weak one only looks alike.
An analogy is a claim that two things share the feature that matters. It is strong when the shared feature is the one the conclusion needs. It is weak when the resemblance is vivid and the relevant difference is ignored.
John Stuart Mill treated analogy as a guide to what to investigate, not as a finished proof. A good analogy tells you where to look. A decorated one tells you how to feel.
Ask: is the likeness the working part, or the paint? If you can swap the image for a plainer sentence and the reason disappears, you had a picture, not an argument.
Running a city like a kitchen
A candidate says, “A city is just a kitchen. A good cook tastes everything, so a mayor should personally approve every contract.” Kitchens and cities both involve feeding people. The scale, the law, and the conflict of interest do not match.
The image is memorable. The reason to approve every contract is still missing. The analogy borrowed the warmth of cooking and spent it on a policy.
Try this today Test one comparison you heard by naming how the two things differ in the way that matters.
Cite or share this lesson
A plain reference you can paste into notes or an essay:
Quest2Reason. “A Weak Analogy.” https://quest2reason.com/learn/lesson/weak-analogy. Accessed 13 November 2026.
Sources
- John Stuart Mill, A System of Logic — Analogy as a prompt to investigate, weaker than a completed induction.
- Stanford Encyclopedia of Philosophy, “Analogy and Analogical Reasoning” — When a similarity carries a conclusion and when it only decorates one.
- Wikipedia, “False equivalence” — Treating two things as alike on thin grounds.