 Nor indeed can we rank, and sort Things, and consequently (which is the end of sorting) denominate them by their real Essences, because we know them not. Our Faculties carry us no farther towards the knowledge and distinction of Substances, than a Collection of those sensible Ideas, which we observe in them; which however made with the greatest diligence and exactness, we are capable of, yet is more remote from the true internal Constitution, from which those Qualities flow, than, as I said, a Countryman’s Idea is from the inward contrivance of that famous Clock at Strasburg, whereof he only sees the outward Figure and Motions. (III.vi.9)