The formation of gestures and the fabrication of knowledge

Among the essential (but almost forgotten) insights of the Age of Enlightenment was the recognition that “human understanding” (Locke 1959 [1690]) – the formation and accumulation of common knowledge – is dependent upon the formation and accumulation of material signs: material entities that reside, however fleetingly, in the public realm where they may be reused and thereby shared; representations that embody a world that may be jointly acted and reflected upon; artifacts that, while products of minds, are nevertheless external to them, providing tools not only for the mind, but also for labor and human self-creation; socially shared cognitive tools that evolve over time as humanity's mind evolves through relying on and refining them.

With this proposition, anti-Cartesian philosophers such as Condillac for the first time directed attention to the importance of symbol systems (or media) for human cognition, self-creation, and society. Condillac in particular recognized the inherently social character of the human mind, and he suggested that signs and insights originate in social practice. He wrote:

Condillac called signs “sensations transformées,” transformed sensations, by which he meant the entire complex of affect, desire, sensory perception, and motor action that makes up what nowadays we might call ‘embodied experience’.