The Renaissance constitutes a new phase in the history of linguistics. The study of modern languages in particular contributed to enlarge the scope of philological concern as scholars try to promote and to codify a young national language. During this time philologists give particular attention to the origin of these vernaculars, distinguishing the different stages in their evolution and developing an especial awareness of chronology. For the representatives of a national philology, Latin is the starting point, the mould according to which the vernaculars are described and classified. Soon, however, more and more traits are recognized which are particular to these living languages, and which do not agree with the traditions of Latin grammar. On the one hand, modifications on the theoretical level are called for, and, on the other, there is a good opportunity to demonstrate the particularity of a given vernacular.

All these tendencies can be found for the first time in the writings on Cas-tillian by the great philologist Antonio de Nebrija (1444–1522). Nebrija recognized a series of phonetic correspondences which, much later in the 19th century, are transformed into ‘phonetic laws’ by a rigorous methodology. In so doing the elaboration of orthographic principles had been for him a stimulus for his explications. In his “Diálogo de la lengua”, Juan de Valdés (devoted himself more extensively to the social aspects of Castillian, to linguistic changes, and to the historical causes for the distribution of Romance languages on the Iberian peninsula, stressing expecially the role of the ‘Reconquista’. The work of Bernardo José de Aldrete (1560–1641) offers a synthesis of all these efforts concerning the evolution of Castillian. He discusses all the substrata and superstrata of the language, sketches the different stages of development of his native tongue, examines Old Castillian with the help of medieval texts, and exploits what Nebrija had noted about the phonetic correspondences. In terms of scholarship, Aldrete’s work constitutes the culmination point in the movement engaged in supporting the rights of the Castillian language et in documenting its sovereignity vis-à-vis the Latin tradition.