This paper focuses on Dante as a linguist who strived to establish the Italian vernacular as a new language. His way of establishing the Italian vernacular was pursued in two ways: the theoretical discussion in his Convivio and De vulgari eloquentia and the creative writing in his Vita nova and Comedy. It would be no overstatement to say that all of his intellectual and creative works were concentrated on examining the possibility of a new language particularly in its roles in the human community that he was facing; they include even his moral attitude and theoretical method in that a language was for him the tool for practicing his mission to link the medieval and modern civilizations. Dante’s enterprise to select and circulate the Italian vernacular was propelled with his firm belief that a language must be able to contribute to communicate human knowledge and emotion. For him the problem of language was on a more practical dimension in that he considered how the language of communication can be produced, circulated and consumed, rather than a logical dimension in that Humanist linguists treated how the language of signification can be systematized and explained. However, he never neglected the possibility and necessity that the vernacular needs to be associated with the Latin as grammatical language. It is in this sense that I call Dante’s Italian vernacular the post-Babel language. If we can call the Latin the pre-Babel language and the Italian as the national language of Italy the after-Babel language, Dante’s Italian vernacular was created and maintained with its nature of ‘in-process’; Dante was distinguished with his attitude not to abandon the different attributions that both languages bore: the Latin as a system and the Italian vernacular as an experience. In this kind of understanding, we can approach Dante’s apparently contradictory mentions on the positions of the two languages. His bilingualism is never simply grasped as the way in which both languages are collaborated in our communicative acts; it rather concerns his endless endeavors to repeatedly cross the pre-Babel and the after-Babel languages. In this process he always considered how a language conveys our experience, emotion and knowledge, and he did not hesitate to conclude that such consideration is necessarily converged in what is called literature. In all, his linguistic pursuit needs to be evaluated as the enormous plan for establishing the literariness as communication and cultural exchanges among the plural languages and cultures.