Who is Ethan from Graven Images and what is their importance?

Ethan is Mrs. Frye's adopted son, who she found abandoned and alone on a country road when he was a mere infant. Mrs. Frye isolated Ethan as a child, keeping him from attending both church functions and refusing to allow him to go to school. She was determined he be an example of good manners and refinement.... Ethan, however, had other ideas. As soon as he was old enough, Ethan left Mrs. Frye's home and ran away to sea.