David Hume's An Enquiry Concerning Human Understanding In David Hume's seminal epistemological work, Section II (in An Enquiry Concerning Human Understanding), "Of the Origin of Ideas," wherein David Hume outlines, with uncommon sharpness and uncanny skill, not only what he believed to be the true origin of what we call ideas, but the way we formulate them. According to Hume, little thought is truly a priori or innate. He believed that thoughts originate from "impressions," or actual sensual experience, that they are simply weak "echoes" of these impress