Since the second century, libraries have been esteemed as keepers of the flame of knowledge and culture. At the stone Library of Celcus, constructed in Turkey in 1100 A.D., for example, 15,000 documents were kept safe from the elements and other destructive forces such as rodents. In places like Celcus, the knowledge of Greek philosophy, Roman technology, and the math and science of the Arabic speaking people were protected and maintained for future generations. The ancient library there bore the carved inscriptions "Wisdom, Knowledge, Intelligence and Virtue." The inscriptions reflect an understanding that this is more than mere collection. They refer to society's aspirations to preserve and sustain the keys to human potential.