What theory does the writer use in this novel?Black Beauty by Anna Sewell

Recognized as the first animal autobiography of
consequence, Anna Sewell's Black Beauty was intended as a book to
enlighten people about the human treatment of animals, especially horses.  This
narrative places the cruel practice of fox hunting, as well as the inhumane, but
fashionable use of the bearing rein into the awareness of the public.  Sewell's skillful
use of detail helps the reader sense the cruel bit biting into Beauty's mouth and the
strained and painful agony he feels under the bearing
rein.

In writing Black Beauty, Anna
Sewell hoped that people would react to the inhumane practices of her day.  In fact, the
publication of her book had the greatest effect upon the human treatment of horses than
any other publication; it brought about the end of the traditional and fashionablel
practices that caused horses to suffer.  in addition, it has brought more humane
treatment of cats and dogs, too.