Relation (n.) is the mind carrying an idea beyond itself — setting one thing beside another and looking from one to the other.
Relation (n.) lets one man be older and younger, stronger and weaker, at the same moment — just by shifting what we compare him to.
A Relation (n.) can hide inside a word that looks absolute: old, great and imperfect seem plain facts about a thing but conceal a comparison.
Relation (n.) can change while nothing changes: Caius, a father today, ceases to be one tomorrow by his son's death, without any alteration in himself.
Relation (n.) can be clearer than the things it relates: I may know clearly what brothers are while knowing nothing of how they were born.
Relation (n.) can be known perfectly between things known dimly: I know which cassowary in St James's Park is dam and which chick, while hardly knowing what a cassowary is.