Divination is the leitmotif of this essay. I tried to analyze this subjet that the main thinkers and philosophers point out as the key-subject of the neoplatonic sage Giambilico's Treatise On the Mysteries of Egyptians. It is a ten books work and the third one was totally focused on Divination by the Author. Here he refutes and debates Porfirio's objections about the nature, the shapes and the teurgic aims the divination art can have. This essay follows the studying method already used in the Comment of the Book III of the Treatise On the Mysteries of Egyptians: in this way i tried to show up and present a fresco about the wide variety of theories, doctrines and contradictions about this subject and describe an original complete cri...