Who is Dr. Donald Warren from Welcome to the Monkey House and what is their importance?

Dr, Donald Warren is the Whitehall headmaster. He was forced to write the hardest letter in the world—letting the Remenzels know that Eli was not accepted. Even harder, he ends up having to tell them this in person. He is very cordial and apologetic. Dr. Warren's concern is that the boy will suffer unduly by being forced to work at Whitehall standards.