Analogy, n.; pl. Analogies.
Etymology: [L. analogia, Gr. analogie. See Analogous.]
1. A resemblance of relations; an agreement or likeness between things in some circumstances or effects, when the things are otherwise entirely different. Thus, learning enlightens the mind, because it is to the mind what light is to the eye, enabling it to discover things before hidden.
Note: Followed by between, to, or with; as, there is an analogy between these objects, or one thing has an analogy to or with another.
Note: Analogy is very commonly used to denote similarity or essential resemblance; but its specific meaning is a similarity of relations, and in this consists the difference between the argument from example and that from analogy. In the former, we argue from the mere similarity of two things; in the latter, from the similarity of their relations. Karslake.
2. (Biol.)
5 more senses
A relation or correspondence in function, between organs or parts which are decidedly different.
3. (Geom.)
Proportion; equality of ratios.
4. (Gram.)
Conformity of words to the genius, structure, or general rules of a language; similarity of origin, inflection, or principle of pronunciation, and the like, as opposed to pl. analogies. Johnson.
Shades of meaning
Analogy is specifically a resemblance of relations; a resemblance that may be reasoned from, so that from the likeness in certain respects we may infer that other and perhaps deeper relations exist. Affinity is a mutual attraction with or without seeming likeness; as, the affinity of iron for oxygen. Coincidence is complete agreement in some one or more respects; there may be a coincidence in time of most dissimilar events. Parity of reasoning is said of an argument equally conclusive on subjects not strictly analogous. Similitude is a rhetorical comparison of one thing to another with which it has some points in common. Resemblance and similarity are external or superficial, and may involve no deeper relation; as, the resemblance of a cloud to a distant mountain. Compare allegory.
Prepositions
The analogy between (or of) nature and revelation; the analogy of sound to light; a family has some analogy with (or to) a state.