Designing Shared Goals to Heal Societies

How do societies work their way out of polarization? And what does the answer have to do with broken trucks, the Apollo program, the movie 'Watchmen', Iroquois Native Americans, a new idea for social media algorithms, moral taste buds, and how we can take advantage of the common threads that bond us -- coming to see each other again as fellow travelers improvising their way through the same noisy world?