" Under the name of guilds, friendships, brotherhoods, universities, etc., associations multiplied: for mutual defence, to avenge affronts suffered by some member of the association and to express solidarity, to replace 'eye for an eye' vengeance by compensation, followed by acceptance of the aggressor into the brotherhood "

― Pyotr Kropotkin , Anarchism, Anarchist Communism, and The State: Three Essays