The development of reflex theory in its Pavlovian interpretation had significant resonance in a wide range of academic research areas. Its impact on the so-called humanities was, perhaps, no less than the effect it had in medical science. The idea of the conditioned reflex suggesting a physiological explanation of behaviour patterns received a particularly warm welcome in philosophy and psychology as it provided a scientifically-based tool for a conceptual u-turn towards objectivism. This article looks into the ways these ideas contributed to the formation of the Soviet language theory, namely, to the sociological interpretation of language development and speech production presented in the pioneering works of Sergej M. Dobrogaev (1873–1952).