Dorothy L. Sayers writes in The Mind of the Maker:
Yet it will not altogether do to say that neither conversion nor coincidence is ever permissible in a story. Both may legitimately be introduced on one condition, that is, that they are an integral part of the Idea. If it is a story about a coincidence or about a conversion, then the Energy that introduces them will be performing the will of the Idea, and the Power will proceed from that unity of purpose. This amounts to saying that, under these circumstances, the will of the creator becomes a character in the story; just as, theologically, all miracles depend on the assumption that God is a character in history.
