“Condemned by church authorities, the fifty-six extant manuscripts nevertheless testify to the seductiveness of that offer.”
The Ars notoria sold medieval students a way to skip university: stare at the right diagrams, recite the right unintelligible words, get the knowledge. Aquinas called it unlawful and futile and said the signs were understood by neither humans nor God. Fifty-six manuscripts survived anyway, and it eventually went to print. The market for paying your way past the hard part of learning has never once gone unserved.