Given the enormous geographical distribution of the Spanish language and the fact that it is the national language of more than twenty countries, the Hispanic world represents an obvious case of linguistic polycentrism. In a situation such as this, there is an apparent need to reconcile two criteria which, at first glance, can seem contradictory in several points. On one hand, there is the obvious advantage of maintaining the possibility of communication between all the Spanish-speaking world; and on the other hand, the need to respect unavoidable linguistic differences which exist within such an extensive and numerous population. This article is particularly interested in the relations between the conservation of linguistic unit and the teaching of Spanish as a mother tongue. As a first point towards achieving this, the present work explores the normative consequences of the phenomenon of linguistic variation in Spanish. It examines the characteristics of this polycentrism and the idea of a common Hispanic norm, guarantor of the unit and which can be considered in different ways: as a superior, general or reference Hispanic norm. As a second point, the papers studies two different cases of educative policy which aim at conserving of linguistic unit. These depend on whether pedagogical objectives take into account or not the phenomenon of linguistic variation: an unidialectal education centered on a Hispanic norm of reference and a pluridialectal education centered on the regional norm. The description and the evaluation of each of these approaches will finally lead us to support a normative liberalism, panhispanic linguistic policy with a variationist approach in the teaching of first language. This would be represented by the approval and the respect for normative diversity but also by the search for reciprocal -and therefore common- linguistic knowledge between the Spanish-speaking, based on dialectal knowledge of each one.