2. Ideas of relations without correlative terms, not easily apprehended.
These and the like relations, expressed by
relative terms that have others answering them, with a reciprocal intimation, as father and son, bigger and less,
cause and effect, are very obvious to every one, and everybody at first sight perceives the relation. For father and
son, husband and wife, and such other correlative terms, seem so nearly to belong one to another, and, through
custom, do so readily chime and answer one another in people's memories, that, upon the naming of either of
them, the thoughts are presently carried beyond the thing so named; and nobody overlooks or doubts of a relation,
where it is so plainly intimated. But where languages have failed to give correlative names, there the relation is
not always so easily taken notice of. Concubine is, no doubt, a relative name, as well as a wife: but in languages
where this and the like words have not a correlative term, there people are not so apt to take them to be so, as
wanting that evident mark of relation which is between correlatives, which seem to explain one another, and not
to be able to exist, but together. Hence it is, that many of those names, which, duly considered, do include evident
relations, have been called external denominations. But all names that are more than empty sounds must signify
some idea, which is either in the thing to which the name is applied, and then it is positive, and is looked on as
united to and existing in the thing to which the denomination is given; or else it arises from the respect the mind
finds in it to something distinct from it, with which it considers it, and then it includes a relation.
