 For Hartley, language is a highly “decomplex” motor activity that involves the cementing of associations between perceived and created sounds, and, for the literate, perceived and created marks: “impressions made on the ear,” “actions of the organs of speech,” “impressions made upon the eye,” and “actions of the hand in writing” (OM 1, prop. 79). Further connections must be made between perceived or created sounds and features of the world, especially the actions of oneself and of other people. Hartley’s approach is nearly the opposite of Locke’s, who writes as if language were a dictionary, in which each word marks an idea known prelinguistically to the speaker: “words being voluntary signs, they cannot be voluntary signs imposed by [the speaker] on things he knows not… . Till he has some ideas of his own, he cannot suppose them to correspond with the conceptions of another man; nor can he use any signs for them” (Locke [1690] 1975, 3.2.2).