In this chapter we address Werner and Kaplan’s (Symbol Formation: An Organismic-Developmental Approach to the Psychology of Language. Wiley, 1963) account of the microgenesis of adult symbol formation. We compare Werner and Kaplan’s view of the dynamic unfolding of inner speech to McNeill’s (Language is Gesture. MIT Press, 2025) growth point theory; in particular to the role of gesture-speech unity, a form of thought that exists uniquely in growth points and is inherent to speaking a language. Our most central proposal is that the microgenetic unfolding of inner speech can be reformulated as a growth point, and in it one sees how discourse cohesion is foundational for meaning-creation and utterance-formation. The line of argumentation is as follows. First, the emergence of cohesion corresponds to Werner and Kaplan’s “significant leap forward” along an ontogenetic trajectory toward compound sentences, “linguistic expressions of relations between thoughts.” Second, a comparison to growth point theory points to sources of cohesion in the inseparability of speech from gesture and of both from context, the latter a function of Vygotsky’s (The Collected Works of L.S. Vygotsky, Problems of General Psychology. Plenum, 1987) “law of sense influence.” In our view, the reformulation of Werner and Kaplan’s account in growth point terms expands understanding of the dynamic dimension of language in inner-dynamic processes of symbol formation.