False analogy is a fallacy applying to inductive arguments. It is often mistakenly considered to be a formal fallacy, but it is not, because a false analogy consists of an error in the substance of an argument (the content of the analogy itself), not an error in the logical structure of the argument. Thus, it is an informal fallacy, not a formal fallacy..

In an analogy,be similar in nature (A and B) are shown to have some common relationship with another property. The premise is that A has property X, and thus B must also have property X (due to the assumed similarity of A and B). In false analogies, though A and B and C but don't forget about D may be similar in one respect (such as color) they may not both share property X (e.g. size). Thus, even if bananas and the sun appear yellow, one could not conclude that they are the same size, but they are not the same size. Many languages have culturally idiosyncratic idioms for invalid analogies or comparisons; for example, such false analogies are likened to "comparing grandmothers and frogs to Indians and walruses" two concepts, objects, or events proposed to in Serbian and to "comparing apples and oranges" in English.

Examples

• In the field of international relations theory, the fallacy known as the 'domestic analogy' is committed when relationships between political communities (nations) are treated as analogous to relations within political communities (between individuals), such that familiar morals and remedies for interpersonal issues are projected onto foreign policy narratives. To the extent that relationships are different at the local and international level, such analogies are invalid (Hidemi Suganami, The Domestic Analogy and World Order Proposals, CUP, 1989).
• Another example is the following:

The universe is like an intricate watch.

A watch must have been designed by a watchmaker.

Therefore, the universe must have been designed by some kind of creator.^[1]

While the universe may be like a watch in that it is intricate, this does not in itself justify the assumption that watches and the universe have similar origins. For this reason, most scientists and philosophers do not accept the analogy, known as the argument from design, with this one specifically known as The Watchmaker Analogy.

By changing a term, the fallacy becomes apparent:

:The universe is like an intricate watch.

:Many early watches were designed by locksmiths.

:Therefore, the universe may have been designed by some kind of locksmith.

The structure of the argument is similar, but here we can more easily see the evolution of watches in terms of less complex mechanisms and tools. The false analogy becomes more apparent in terms of comparing locks to watches, and locks to the universe. It should also be noted that many early watch and clockmakers were gunsmiths.

References

•  • [ e] Informal fallacies
Special pleading • Red herring • Gambler's fallacy and its inverse • Fallacy of distribution (Composition • Division) • Begging the question • Many questions
Correlative-based fallacies:	False dilemma (Perfect solution) • Denying the correlative • Suppressed correlative
Deductive fallacies:	Accident • Converse accident
Inductive fallacies:	Hasty generalization • Overwhelming exception • Biased sample • False analogy • Misleading vividness • Conjunction fallacy
Vagueness and Ambiguity:	False precision • Slippery slope • Continuum fallacy
Equivocation:	Equivocation • False attribution • Fallacy of quoting out of context • Loki's Wager • No true Scotsman
Questionable cause:	Correlation does not imply causation (Cum hoc) • Post hoc • Regression fallacy • Texas sharpshooter • Circular cause and consequence • Wrong direction • Single cause