Catherine Earnshaw was supposed to be the same character in the 1847 book Wuthering Heights, by Emily Brontė, and the 1939 screenplay Wuthering Heights, by Ben Hecht and Charles MacArthur, but two different Catherines emerged. One was strong and self absorbed; the other was weak and love-sick. The different Catherines are there from the beginning to the end. With all the differences between the book and the screenplay, which was made into a movie in 1939 directed by William Wyler, the character change in Catherine could not be ignored.

     The book showed the reader a Catherine Earnshaw, later to be Catherine Linton, that was something of a villainness. She wanted the best of both worlds, while refusing to give in to anyone. Catherine longed for the parties and fine clothes with Edgar Linton, but also wanted to be with the dark and mysterious Heathcliff. In the book, Catherine and Heathcliff have a violent love-hate relationship. They do not, however, confess their love as openly as the screenplay and film have them do.

     The screenplay and film show a weak Catherine whom the reader cannot help but feel sorry for. Catherine and Heathcliff, confess their love for each other as youngsters (Sarita Wooten and Rex Downing) and as adults (Merle Oberon and Laurence Olivier) while Catherine's undying love for Heathcliff is seen again and again throughout the screenplay and film.

     The Catherine in the book shows a hard quality by using people to get what she wants. She uses Edgar to get the quality of life she wants. Although she and Heathcliff have some sort of love, they never really admit it openly. She almost seems incapable of love. Catherine longs for the madness of Heathcliff, but also for the money of Edgar Linton. She never really chooses one of them, leaving the feeling that she never loved anyone. Her torment between her past and her married life is in the scribbling of her name "Catherine Earnshaw" and then writing "Catherine Linton." Her tormented struggle between her two identities eventually leads to her death.

     In the screenplay and film, Catherine seems to have no real agenda. She is like a pawn in a game who has no say in what happens to her. Although she does marry Edgar (David Niven) for his money, the reader feels almost sorry for her because she is so weak. Her love for Heathcliff makes her a helpless woman who needs a man.

     The Catherine in the screenplay does not do justice to the Catherine in the book. The two are almost opposites in character, with only main life events tying them together. Wuthering Heights had a strong leading lady in the book and a diluted version in the screenplay.