This Essay identifies a set of epistemological and normative assumptions underlying the presentation of doctrines on marriage and parent/child relationship law in the canonical family law treatises of Latin America. I refer to this set of premises as the social approach to family law and argue that this approach has a distinctive impact on the arguments that should be construed, could be construed, and could not be imagined within family law. I suggest that the successive reforms of marriage and parent I child relationship law in Latin America in the twentieth century, and the practices related to these reforms, are best understood when these premises are taken into consideration.