6. The cause of such reference.
These suppositions the mind is very apt tacitly to make concerning its own ideas.
But yet, if we will examine it, we shall find it is chiefly, if not only, concerning its abstract complex ideas. For the
natural tendency of the mind being towards knowledge; and finding that, if it should proceed by and dwell upon
only particular things, its progress would be very slow, and its work endless; therefore, to shorten its way to
knowledge, and make each perception more comprehensive, the first thing it does, as the foundation of the easier
enlarging its knowledge, either by contemplation of the things themselves that it would know, or conference with
others about them, is to bind them into bundles, and rank them so into sorts, that what knowledge it gets of any of
them it may thereby with assurance extend to all of that sort; and so advance by larger steps in that which is its
great business, knowledge. This, as I have elsewhere shown, is the reason why we collect things under
comprehensive ideas, with names annexed to them, into genera and species; i.e., into kinds and sorts.
