The terms casa and rua speak to an internal division in the life of every resident on the Alto, an internal division engendered by the reality of class divides. The author argues that the dynamics of class governs relations among the residents of the Alto in distinct and rigid ways, depending on if one is in public(rua), or in their home (casa).

On the surface, the division between casa and rua is a division between the individual as defined by their socioeconomic role within the implicit caste system of the Alto. For example, those of the pobres generally bear a certain level of dependency and inferiority towards the planting and professional classes, evident in terms of address and familiarity. How they regard one another, and what it is acceptable to ask and expect from one another, will be affected by these roles. Moreover, a certain amount of intimacy is precluded, simply due to the distinction of classes. By this token, members of different classes will appear differently to one another; beyond this, however, members of the same class may only expect a certain aspect of one individual in public, or from their rua identity.

Repression―official and unofficial―is an unavoidable component of the idea of rua, and its negation through casa.