Howe had recently met Julia Brace, a deaf-blind resident at the American School for the Deaf who communicated by using a series of primitive signs; however, her instructors had failed to teach her more advanced methods of communication, such as tactile sign language.[12] Howe developed a plan to teach Bridgman to read and write through tactile means — something that had not been attempted previously, to his knowledge. Howe's plan was based on the theories of the French philosopher Denis Diderot, who believed the sense of touch could develop its "own medium of symbolic language."[13] At first he and his assistant, Lydia Hall Drew, used words printed with raised letters, and later they progressed to using a manual alphabet expressed through tactile sign.[14] Eventually she received a broad education.