At the beginning of the play, Marlowe establishes the image that Faustus has a great hunger for knowledge. When the devil brings various apparitions before him, Faustus comments that these things feed his soul. Each time that Faustus wants to enter into a discussion of the noble things of the world, Mephistophilis shows him something which would appeal to his baser nature and thus satisfy his physical desires. Mephistophilis and Lucifer even parade the seven deadly sins before Faustus, and the appearances of these loathsome apparitions evokes from Faustus the comment, "O, this feeds my soul."
During the course of the drama, the manner in which Faustus satisfies his appetites brings about his damnation. Even at the end of his twenty-four years, he signs a second contract in order to satisfy his carnal appetites by having Helen of Troy as his paramour. Finally in the last scene, he comes to the realization that his appetites have been directly responsible for his downfall. The manner in which he has fulfilled his desires has brought damnation upon himself: "A surfeit of deadly sin that hath damned both body and soul."