In the 13th century, a monk made a practical decision about church property. Vellum was a luxury, a valuable asset, and his investment in a new prayer book required a source. He found an old Greek codex, its mathematical text seemingly irrelevant to his spiritual enterprise. With careful scraping, he erased the ink, seeing the recycled parchment as a success for his monasterys business. He was unaware he was destroying an irreplaceable piece of intellectual history. The development of his prayer