First try to make him understand books are our real friends.
books are our god.
each book is made out by each tree .
so if we tear pages from books , in one way we r killing trees that is we r harming ourselves . our duty to save trees .
and if he continues to tear pages again , its our duty to inform the incharge teachers of the library. becoz in one way we r saving the life of a tree. n in anthr way we r saving all living organisms.
hope it can help u......