Aiming at reconstructing the prologue to On Nature, the first part of this chapter focuses on the collocation of the demonological fragments which, by expanding on Empedocles’ exile introduced in B 115, depict his katabasis into the realm of the dead. The narrative of this extraordinary journey serves Empedocles as authorial legitimation on matters beyond ordinary human knowledge. The second part of Chapter 2 reconstructs the rest of the proem by interweaving traditionally introductory themes, such as the dedication to Pausanias and the invocation to the Muse, with novel topics concerning the rejection of ritual sacrifice based on Empedocles’ concept of rebirth. The proem thus reconstructed presents a coherent programmatic structure and makes sense of several Empedoclean fragments that are essential for a comprehensive and impartial understanding of his thought. Moreover, by showing that religious concerns inform the entire introductory section, the new proem indicates that the concept of rebirth is central to Empedocles’ physical system and thus offers a new basis to rethink the interplay of myth, religion, and physics in his natural philosophy.