Lev Vygotsky’s (1896–1934) views of the genesis of language and its relation to thought, illustrated here by his account of the origin of the pointing gesture, can be seen as anticipating current research in socially constituted cognition, pragmatics, developmental psychology and grammaticalization, in all of which the importance of contextual and pragmatic factors looms large. His conceptualization of the evolution of communication from action to semiosis has bearing on, and is illuminated by, recent developments in neurobiology, developmental psychology, primatology, and grammaticalization theory. Specifically, recently discovered mirror neuron systems may offer a neurophysiological platform for the evolution of language from gesture and imitation, for the transition from action to sign, from referential to relational meaning, an evolution in which the establishment of joint attention is pivotal. With his emphasis on the dynamic, socially constructed nature of signs, Vygotsky shares Humboldt’s view of language as energeia, as a system in a perpetual state of emergence, a view consistent with Condillac’s ‘language of action’, in which spontaneous vocalizations and gestures give rise to sign functions. Research of the grammaticalization pathways associated with demonstratives and modal particles also offers new perspectives on the process and hypothesized unidirectionality of grammaticalization, including the plausible claim that demonstratives represent a second and separate source of candidates for grammaticalization. Integrating grammaticalization research with findings from relevant social and natural sciences holds out the prospect of underwriting significant advances in understanding the origin of language and the emergence of grammar.