I hope I'll be forgiven for including this piece about the infamous Priory of Sion, which, as, anyone who has read The Da Vinci Code can tell you, is a secret organization dedicated to keeping the secret of the Holy Grail — an organization led down the centuries by eminent scientists, thinkers and artists including Da Vinci himself. While not strictly philosophical, this article is an excellent exercise in the kind of scrupulous detective work rarely done by those who spread such myths. It also nicely illustrates how such myths are often started.