The Livro Anteprimeiro da História do Futuro, by Father Antonio Vieira (1608 - 1697), should be a prolegomenon to a larger prophetical work, the History of the Future, which would end up not being concluded. There one can find the basis for a treatise of prophetical interpretations presented as a “historical” work. To achieve such aim, Vieira recurred to classical historiographical and rhetorical elements, mainly as regards to the demonstration of the veracity of his report. Whether due to the context that emerged after the Council of Trent, which was not prone to ideas suspected of heterodoxy, or to the circumstances of the process that Vieira would face later in the Holy Office, that strategy served as a form to create a distance between its author and a polemical issue such as prophecy, as well as a form to impress persuasive force to his ideas.