Lest I give the impression that Reid picks only on Locke, I should note with due haste that he also has little patience with Hume's account of memory.  Recall that Hume's theory is that a memory is an idea that is less vivid and forceful than an impression but more vivid and forceful than an idea of imagination.  Always the attentive reader, Reid quotes the passage from Hume's Treatise of Human Nature in which Hume offers his initial characterization of memory.  At the beginning of Book I, Part I, Section III of the Treatise, Hume writes “We find by experience when any impression has been present with the mind, it again makes its appearance as an idea; and this it may do after two different ways,” one of which is by memory.  Reid asks what Hume could mean by experience in the quoted sentence.  Reid can think of only one plausible answer: memory.  So while Hume offers us a deflationary account of memory according to which to remember something is merely to have an idea that is midway between an impression and an idea of imagination, he helps himself in forming the account to experience which, Reid argues, turns out to require the robust memory of common sense.  Reid says,