  In Cursory Reflections, Norris presses Locke about the nature of an idea. Locke's account of ideas as originating in sensation and reflection found at 2.1 of the  Essay is met by Norris with: “These indeed are pretty Smiling Sentences. But before we go a step further I would willingly know of the Author what kind of things these Ideas are which are thus let in at the Gate of the Senses” (22). Norris infers that Lockean ideas must be either mental substances or modifications, and then presents difficulties for either option. For Norris, the foundation of intelligibility can never have an empirical basis. The foundation must be the true nature of ideas: