Were I to talk with any one of a sort of birds I lately saw in St.
James's Park, about three or four feet high, with a covering of
something between feathers and hair, of a dark brown colour, without
wings, but in the place thereof two or three little branches coming down
like sprigs of Spanish broom, long great legs, with feet only of three
claws, and without a tail; I must make this description of it, and so
may make others understand me. But when I am told that the name of it
is CASSUARIS, I may then use that word to stand in discourse for all my
complex idea mentioned in that description; though by that word, which
is now become a specific name, I know no more of the real essence
or constitution of that sort of animals than I did before; and knew
probably as much of the nature of that species of birds before I learned
the name, as many Englishmen do of swans or herons, which are specific
names, very well known, of sorts of birds common in England.


35. Men determine the Sorts of Substances, which may be sorted
variously.

From what has been said, it is evident that MEN make sorts of things.
For, it being different essences alone that make different species, it
is plain that they who make those abstract ideas which are the nominal
essences do thereby make the species, or sort. Should there be a body
found, having all the other qualities of gold except malleableness, it
would no doubt be made a question whether it were gold or not, i.e.
whether it were of that species. This could be determined only by that
abstract idea to which every one annexed the name gold: so that it
would be true gold to him, and belong to that species, who included not
malleableness in his nominal essence, signified by the sound gold; and
on the other side it would not be true gold, or of that species, to him