Charlotte Mason was a British educator-reformer and one of her main priniciples is that children have minds and are capable of understanding exquisitely written literature.  Living Books replaced dry facts in textbooks or dumbed down books and allowed children to engage in subjects, bringing a heighten child's interest in the topic.   As children read, they learn about the topic unconsciously. they retain more information as they can tether it to an interesting story.

 

A Living Book makes the subject come alive because the author has a passion for the subject.  When this narative is well written it should contect the reader that fires up their emotion and imagination.   A Living Book will also contain ideas that will feed the readers mind to spark new ideas.  When all these components come together in a book, then it's a Living Book.