Now, since nothing can be a man, or have a right to the name man, but what has a conformity to the abstract idea the name man stands for, nor anything be a man, or have a right to the species man, but what has the essence of that species; it follows, that the abstract idea for which the name stands, and the essence of the species, is one and the same.

From whence it is easy to observe, that the essences of the sorts of things, and, consequently, the sorting of things, is the workmanship of the understanding that abstracts and makes those general ideas.
13.

They are the Workmanship of the Understanding, but have their Foundation in the Similitude of Things.
I would not here be thought to forget, much less to deny, that Nature, in the production of things, makes several of them alike: there is nothing more obvious, especially in the races of animals, and all things propagated by seed.

But yet I think we may say, THE SORTING OF THEM UNDER NAMES IS THE WORKMANSHIP OF THE UNDERSTANDING, TAKING OCCASION, FROM THE SIMILITUDE IT OBSERVES AMONGST THEM, TO MAKE ABSTRACT GENERAL IDEAS, and set them up in the mind, with names annexed to them, as patterns or forms, (for, in that sense, the word FORM has a very proper signification,) to which as particular things existing are found to agree, so they come to be of that species, have that denomination, or are put into that CLASSIS.

For when we say this is a man, that a horse; this justice, that cruelty; this a watch, that a jack; what do we else but rank things under different specific names, as agreeing to those abstract ideas, of which we have made those names the signs?
And what are the essences of those species set out and marked by names, but those abstract ideas in the mind; which are, as it were, the bonds between particular things that exist, and the names they are to be ranked under?
And when general names have any connexion with particular beings, these abstract ideas are the medium that unites them: so that the essences of species, as distinguished and denominated by us, neither are nor can be anything but those precise abstract ideas we have in our minds.