Verenikina discusses Vygotsky's contribution, beginning with the remark that "Vygotsky's life goal was to create a psychology adequate for the investigation of consciousness. He stated that consciousness is constructed through a subject's interactions with the world and is an attribute of the relationship between subject and object." Vygotsky also provided a "concept of the mediation of elementary (natural) mental processes by psychological tools (artificial devices for mastering mental processes) and internalisation." Vygotsky provided the initial impetus towards activity theory by introducing the notion of tool as a form of "mediated action" which "is externally oriented [and] must lead to changes in objects". Luria explains this: "Vygotsky supposed that higher mental processes are of a social origin... he suggested that the simplest form of [human conscious] behaviour can be found in tool- or sign-using, where a tool (or sign) can be used to reach a certain goal. Instead of the elementary scheme S?R (‘S’ for stimulus, ‘R’ for reflex), he proposed a new scheme S? x? R) where S stands for stimulus, x for means (tool or sign), and R for reflex."

Thus, Luria goes on to argue, explanation of complex phenomena such as human activity "is supposed to lie not in its reduction to single elements but rather in its inclusion in a rich net of essential relations."