Fruit of the efforts of an entire literary life, Vico s theory of poetic characters, master-key of the New Science, is an original theory of metaphor, critically placed against Cartesian widespread methodology. Nevertheless, Vico s science does not belong to the domain rejected by Descartes of the human sciences or the cultural sciences. Actually, although Vico qualified his science new, he saw his Science as part of the tradition of sciences of the seventeencentury, as he incorporates the axiomatic disposition of Spinoza and the careful observation of Bacon (that he transferred from the natural to the civil world). The original metaphor of Jove, that establishes the centrality of the trope in Vico s philosophy, allow us to review the so said theory of history present in germ in his Science, and, in so doing, to restore the three ages (of the gods, heroes and men), that take us from poetry to prose, as interpretative tools acting always simultaneously. It is actually the originary and inventive qualities of Jove s metaphor – and of the poetic characters in general – that guides Vico on the exam of the signs, with which he establishes a mental dictionary. With this dictionary it is possible to comprehend the language that speaks the ideal eternal history. Therefore the book dedicated to the poetic wisdom is particularly important. The poetic characters composed by induction of similarities, sustain Vico s historical topology and Vico s science. This remarkable theory of language answers with precision the main challenges found on the debates around the concept of ingenuity, that animates the Italian and the Spanish poetologies of Góngora, Marino, Gracián, Peregrini, Tesauro and Pallavicino. At the center of the question, we find the legitimation of the metaphorical invention as a mode of knowledge that sustains Vico s topical philosophy by philology. Finally, we ll see that, once established the bases of Vico s topic, the principle that attributes to human deeds its own truth (verum ipsum factum) suggests a theory of fiction.