Summa Universalia

While Principia Discordia is often said to be the seminal Discordian work, the book itself disagrees (at least in its first edition) and claims to have taken material from an earlier work, Summa Universalia. (This includes the famous and long-missing The Myth of Ichabod, more popularly known as The Myth of Starbuck, which was uncovered in 2006 in the John F. Kennedy archives). The work isn't mentioned at all in the Fourth Edition of Principia Discordia, the only edition in common distribution (other than the one-page "fifth edition" included in some versions of the fourth edition). It's unknown whether this is an actual work, or was an early Discordian concept that was never completed.