Whilst it can be argued that a crucial aspect of the transition from the medieval world to the modern is the move from a kin-based model of society to one based on friendship of mutual advantage, we must be wary of inferring too great a break. Alan Bray has shown that the idea of ‘sworn brotherhood’ persisted much longer than was previously acknowledged; the model of family as the basis for friendship persisted. Montaigne, though arguing that friendship is superior to brotherhood, acknowledges that ‘Verily the name of Brother is a glorious name, and full of loving kindnesse, and therefore did he [his friend Etienne de la Boëtie] and I terme one another sworne brother.’ If friendship is to some extent modelled on brotherhood, to understand the problems of brothers will help us to see both what friendship was competing against and what it was based upon. There is a more obvious tension between brothers than between friends: Sir Thomas Elyot argued that there is a crucial difference between friendship and kinship in that ‘from kynrede may be taken beneuolence, from frendship it can neuer be seuered. Wherfore beneuolence taken from kynrede yet the name of kinseman remayneth. Take it from frendship and the name of frendship is utterly perrished.’ The tension between brothers as represented in Shakespeare's plays is deeply related to friendship.