In the classic movie, Mary Poppins, Julie Andrews plays a no-nonsense, yet delightful, nanny to two young children. As a nanny to a wealthy family, she is part teacher, part parent, and part disciplinarian. She gets the children up in the morning, puts them to bed at night, supervises their many adventures, and guides them in many ways. While they are in her care, she is responsible for their overall safety and well-being.

In the ancient world, wealthy Greek and Roman families would assign this kind of responsibility to a slave called a paidagogos. He was usually an older male slave, charged with the responsibility of caring for a young boy through childhood into adulthood. At times, he might need to be a disciplinarian; at other times more of a teacher; at other times more of a superviso…