Throughout history, human beings have been defined by what they DO - parent, merchant, spouse, employee, citizen. Full adulthood, or full membership in the community, was based on a person's ability to meet the expectations that were asked of them in terms of generating income or providing support for others. Being able-bodied was an essential part of the act of Be-ing human.
And yet, in many societies, people took a more expansive view of what it means to be human. In tribal and indigenous societies, disability was seen as part of a spectrum that included a non-binary,