The chapter looks at period boundaries – c. 500, c. 1000 – and ways of transcending them. To position oneself on a boundary is one way, and another is to look for deep continuities. Here additional schemas have been proposed: the re-emergence of a half-submerged system with the recurrence of the conditions that gave rise to it originally, and, above all, the evolution of a sequence of communications (as opposed to a constant idea) like a conversation, from its origin through its twists and turns over many centuries. The history of the first papal jurisprudence’s reception over time can be a ‘part for the whole’, a synecdoche for the changes in history of Western Christianity. Tracing its reception helps to subvert the apartheid of periodization.