This is my third book to focus on the nexus of gesture and language. Together, the three amount to a kind of unintended trilogy, what has turned out to be a sustained examination and ultimate explanation of a certain phenomenon. The first, Hand and Mind (1992), introduced what was then a newly discovered world of gesture, not the stand-alones (known as emblems) that have been acknowledged for millennia, but those overlooked but omnipresent gestures that wed themselves to speech itself. The second, Gesture and Thought (2005), developed an explanation of this wedding, the growth point. Now I tackle the origin of the growth point in evolution. By this third volume I am aware of having run far out on a limb. Out on a limb because in crafting the book I have followed a line of argument to its logical limit, or as close to a limit as I can get. The line is that language is more than the lexicosyntactic forms that one sees in written texts and the analyses of linguistics. It is also imagery. This imagery is in gesture, and is inseparable from language. The hypothesis of a growth point encompasses this idea. Taking seriously that language includes gesture as an integral component changes the look of everything. We see language in a new way, as a dynamic “language-as-action-and-being” phenomenon, not replacing but joining the traditional static (synchronic) “language-as-object” conception that has guided linguistics for more than a century.