This text tries to give some initial scopes for a constructivist approach to political philosophy and social organization based on the fact of friendship; particularly in the greeting taken as an event of friendship. The mere greeting, the most basic approach to empathy, would be the happening of a world, of a whole world characterized by its demand to be, to be realized and preserved. This requirement would come from an unfathomable archaic background, which would be accessible in the idea of the number of friends. It is an aporia that shows both the open, but not infinite, character of a reference group based on the tenderness of something common.