The Principia Discordia was assembled by Greg Hill and Kerry Thornley in the early 1960s and circulated in photocopied editions with no copyright and an explicit invitation to reproduce it. It is a collage of collage: mock scripture, cartoons, rubber-stamped seals, blank pages labelled as containing something, and a set of doctrines about Eris, the goddess of discord, and about the tension between order and disorder.
Discordianism sets two principles against each other. The Aneristic principle is the apparent order that the mind imposes on experience; the Eristic principle is the disorder underneath. The Sacred Chao, the movement emblem, holds a pentagon and an apple in the positions where a taijitu holds its two halves, and the pentagon is the Aneristic side. That is why five recurs across the iconography and why the Law of Fives sits where it does in the text.
The book also hands out its own authority freely. Every reader is a pope, by way of a card the Principia reprints for the purpose, and the movement has no membership, no hierarchy and no means of excluding anyone. That structure is not incidental to the Law of Fives; a doctrine about the manufacture of patterns is more effective in a religion where nobody has the standing to rule on what it means.