Focusing on the picaresque novel, a genre which has constantly defied definition, this dissertation analyzes the nature of and relationship between literary and social boundaries, and the "Others" that these boundaries create. By analyzing picaresque texts that are excluded from the picaresque canon, this dissertation intends not to defend their inclusion or exclusion in the genre (an issue that has already been exhaustively debated) but, in a new approach, to identify the ideological and social mechanisms that define generic boundaries. The study thus becomes one of literary and social convention and the consequent marginalization of texts and social actors. I explore the limits---or margins---of the picaresque from several points of view: the social marginalization of women and its reflection in pícaras (female rogues); the defiance of literary and social convention in Cervantes' Novelas ejemplares; and the striking parallelism between the Vida of Santa Teresa de Ávila and picaresque modes of narration. The feminine picaresque, Cervantes' pícaros, and the Vida of Santa Teresa constitute texts whose inclusion in the picaresque genre is as uncomfortable as their exclusion. And yet it is for just this reason that they offer a novel means of investigating the ideological mechanisms that define the border of literary and social acceptance.