In A Theory of Justice (1971) John Rawls asks you to choose a society’s rules behind a veil of ignorance, where “no one knows his place in society”. He thought you’d make sure the worst place was as good as it could be. He meant a society’s basic institutions, not cake.
How to play it
Cut the cake. Then cut it again without knowing which seat is yours.
That’s the whole collection examined, every room. Now imagine doing this with your own life, for a year, with two people who come to know it well. That’s membership.