In this study, I examine communication in the vernacular in the works of François Rabelais, Joachim Du Bellay, and Michel de Montaigne. I analyze these issues in tandem with similar concerns in early modern French and Italian treatises on the vernacular, and argue that, pervasive in the literature of the period, they are best studied with a sociolinguistic eye, focusing less on orthographic and lexicographic changes in the vernacular, and more on issues that question regional dialect and ideas of 'speaking naturally' and 'mother tongue.' In chapter one, I study Rabelais' use of the vernacular, and argue that via the regional dialects he elects for his characters, he is subtly promoting his own dialectal preferences, which reflect those of the sixteenth-century society he lived in. I examine Rabelais in conjunction with the Italian questione della lingua, and argue that his vision of the vernacular is distinct from Dante's vision of a lingua curiale. In electing the dialects of the Loire Valley and Ile-de-France as superior dialects in his books, he actually shares much with promoters of the Florentine dialect, such as Machiavelli. In chapter two, I look at vernacular sources in the poetry of Du Bellay. I argue that while the young Du Bellay has ambitions for 'embellishing' and 'illustrating' the vernacular, he ultimately regrets abandoning native, French sources. I examine Du Bellay's claims about French in the Deffence with those of an adversary, Barthélémy Aneau, and show that in his own career, Du Bellay realizes to be true everything that Aneau criticizes him for, including his failure to recognize the links between France's linguistic history and its national literary history. In chapter three, I study Montaigne's paradoxical relationship with the vernacular. I examine the author's desire to create a personalized system of communication within the restraints of a necessarily societally-determined vernacular. I also examine the author's anxiety about composing in a linguistic system which he senses is constantly changing. I look at this in tandem with similar claims by the treatise-writer Charles Bovelles, and examine the theme of Babel in the works of both.