Hurford's rejects Keller's assumption that communication depends on all participants' sharing of rules of usage and critiques Keller's view of such rules as extrapersonal social realities, arguing that Keller's concepts of symptom, icon, and symbol can be safely reformulated in a framework of intrapersonal psychological rules of usage.(Copyright 1993, Sociological Abstracts, Inc., all rights reserved.) (J. Hitchcock in LLBA 1993, vol. 37, n. 3)