Other forms: analogies
An analogy explains one thing by holding it beside another that works the same way. The heart is a pump; the atom is a tiny solar system; memory is a filing cabinet. The point is not that the two are alike in general, but that one particular relationship carries across.
It is not the same as a metaphor. A metaphor says a thing is another thing and leaves you to feel the resemblance; an analogy is an argument, and it can be tested. That is why you draw an analogy, and why somebody can say the analogy breaks down — the moment the two stop behaving alike, the explanation stops working. In logic and law, reasoning by analogy is a recognised move and a contested one, because the whole weight of it rests on the two cases being alike in the way that matters.
1nounanalogyA comparison that explains something by showing how it works like something else.
“She explained the tax with an analogy about buckets and taps.”
synonyms: comparison, parallel
2nounlikenessA likeness between two things that lets you reason from one to the other.
“The court reasoned by analogy with an earlier case.”
analogy is a kind of comparison.
Also accepted in games: comparison
Ancient Greek analogia meant proportion — literally a matching ratio, the ana- of according to plus logos, reckoning. It began as a term in mathematics: two pairs of numbers standing in the same relation. An analogy still asks for exactly that, with things instead of numbers.
Proto-Indo-European
*leǵ-
Ancient Greek
ἀναλογίᾱ
Latin
analogia
English, today
analogy
Built from
From Latin analogia, from Ancient Greek ἀναλογίᾱ, from ἀνα- + λόγος (“speech, reckoning”).
Etymology from Wiktionary, CC BY-SA
Practised in Big Ideas, Academic English