Document Type

Book Chapter

Department or Administrative Unit

Primate Behavior and Ecology

Publication Date



Truly discontinuous, all-or-none phenomena must be rare in nature. Historically, the great discontinuities have turned out to be conceptual barriers rather than natural phenomena. They have been passed by and abandoned rather than broken through in the course of scientific progress. The sign language studies in chimpanzees have neither sought nor discovered a means of breathing humanity into the soul of a beast. They have assumed instead that there is no discontinuity between verbal behavior and the rest of human behavior or between human behavior and the rest of animal behavior—no barrier to be broken, no chasm to be bridged, only unknown territory to be explored.


This book chapter was originally published in The Cognitive Animal: Empirical and Theoretical Perspectives on Animal Cognition. The full-text book from the publisher can be found here.


© 2002 Massachusetts Institute of Technology