We have the capacity to act together in shared intentional and shared cooperative ways. This lecture argues that our capacity for the plan-based, mind-supported cross-temporal organization of our individual activities, together with certain further elements, suffices for our capacity for the mind-supported, small-scale social organization characteristic of acting together. These two fundamental forms of human practical organization––diachronic and small-scale social––are for us grounded in a common core: our capacity for planning agency.
