Considering the psychogogical capacity of language, that is, its ability to seduce and to convince, this article inquires how this manifests itself in the construction of fantastic literature and in particular in the works of H.P. Lovecraft. Thus, it constitutes an ap- proximation to the fundamental text of the Cthulhu cycle that highlights the rhetorical resources used by its author to convince the reader of the existence of the impossible, as well as of human insignificance in the vast cosmos. Although in these tales all pisteis or means of persuasion ( logos , pathos and ethos ), described by Aristotle, are present, it is evident that, given the importance of the effect and therefore of the receiver of thetext, pathos has a central place.