The nature therefore of relation consists in the referring or comparing two things one to another; from which comparison one of both comes to be denominated.  And if either of those things be removed, or cease to be, the relation ceases, and the denomination consequent to it, though the other receive in itself no alteration at all; v.g.  Caius, whom I consider to-day as a father, ceases to be so to-morrow, only by the death of his son, without any alteration made in himself.  Nay, barely by the mind’s changing the object to which it compares anything, the same thing is capable of having contrary denominations at the same time:  v.g.  Caius, compared to several persons, may truly be said to be older and younger, stronger and weaker, &c.

6.  Relation only betwixt two things.

Whatsoever doth or can exist, or be considered as one thing is positive:  and so not only simple ideas and substances, but modes also, are positive beings:  though the parts of which they consist are very often relative one to another:  but the whole together considered as one thing, and producing in us the complex idea of one thing, which idea is in our minds, as one picture, though an aggregate of divers parts, and under one name, it is a positive or absolute thing, or idea.  Thus a triangle, though the parts thereof compared one to another be relative, yet the idea of the whole is a positive absolute idea.  The same may be said of a family, a tune, &c.; for there can be no relation but betwixt two things considered as two things.  There must always be in relation two ideas or things, either in themselves really separate, or considered as distinct, and then a ground or occasion for their comparison.

7.  All Things capable of Relation.

Concerning relation in general, these things may be considered: 

First, That there is no one thing, whether simple idea, substance, mode, or relation, or name of either of them, which is not capable of almost an infinite number of considerations in reference to other things:  and therefore this makes no small part of men’s thoughts and words:  v.g. one single man may at once be concerned in, and sustain all these following relations, and many more, viz. father, brother, son, grandfather, grandson, father-in-law, son-in-law, husband, friend, enemy, subject, general, judge, patron, client, professor, European, Englishman, islander, servant, master, possessor, captain, superior, inferior, bigger, less, older, younger, contemporary, like, unlike, &c., to an almost infinite number:  he being capable of as many relations as there can be occasions of comparing him to other things, in any manner of agreement, disagreement, or respect whatsoever.  For, as I said, relation is a way of comparing or considering two things [dropped line] from that comparison; and sometimes giving even the relation itself a name.

8.  Our Ideas of Relations often clearer than of the Subjects related.