Sometime during the Palaeolithic, someone discovered he could use his body to understand and express something he perceived. After a while – perhaps days, perhaps generations, perhaps longer – someone else realized she could use material forms for similar ends, obtaining a wider range of expressive outcomes with greater complexity. Like the body, material forms made the percept visible and tangible, visibility and tangibility made it manipulable, and material forms had greater manipulability and could preserve and accumulate those manipulations to even greater extents than the body could. And whether the body or material forms were used, the behaviors involved were communal: Members of the social group not only performed the behaviors themselves, they also witnessed others performing them. This collaboration took many forms: Some members of the group used their bodies, others the material forms, still more manipulated the material forms into new configurations, and many witnessed and understood what was occurring. Over time, the material forms in question changed in ways that made them better at producing desirable effects, while the effects they produced became more elaborate. This meant that greater amounts of time, practice, and instruction were required to master the material forms in order to produce the desired effects. At the same time, most members of the society understood what was going on and were able to participate in the cultural system.