William Wyler's Wuthering Heights falls just short of capturing the emotions and relationships in Emily Brontë's 1847 novel to be a successful film. By successful, I mean marketable, appealing to the general public. A film true to the complex characters of the book would have been more enriching, more thought-provoking to an academic/literary crowd, but it would not have made such a significant mark in the history of pop culture. There is a pop song from the '90s that mentions Heathcliff and Romeo in the chorus; the artist is lamenting the fact that even if he were as desirable as Heathcliff or Romeo, the girl he likes would still refuse him. Anyone who has read Brontë's Wuthering Heights will find this amusing considering Heathcliff's sadistic and morose character. We have William Wyler to thank for our present-day perception of Heathcliff's character and the overall story of Wuthering Heights. Wyler knows exactly what elements of the story to change and what to leave alone.
Fortunately, Wyler knows the novel's characters need simplifying and/or softening. In the novel, the characters' actions leave the reader asking why and trying to tie up loose ends that are resolved. For example, it appears Hindley has good reason for resenting Heathcliff when the violin his father bought him breaks on account of Heathcliff. However, as the boys become acquainted, Heathcliff exhibits a vindictiveness toward Hindley that is largely unexplained, as is evident in the scene where Heathcliff takes Hindley's horse from him. This scene is reversed in the film, and it makes more sense that Hindley (Douglas Scott), being jealous, demands Heathcliff's horse. Of course, Heathcliff's violin is not broken in the film (he gets his intact but is never seen playing it), a missing detail which could cause confusion regarding his intense jealousy. However, it is evident there is reason enough for competition between the two boys; the violin is unnecessary.
Wyler also makes Heathcliff (Laurence Olivier) a more sympathetic character by leaving out the scene where he hangs Isabella's dog and the scene where he digs up Cathy's corpse. Not only is Heathcliff more likable; but also this change renders Isabella (Geraldine Fitzgerald) a more sympathetic character. In the novel, she has had evidence of Heathcliff's low character; and she still chooses to run off with him.
Catherine (Merle Oberon) is easier to swallow in the movie. The worst she does to Linton (David Niven) is give him a verbal lashing after returning from the Grange and encountering Heathcliff. In the novel, she physically attacks Linton. Furthermore, she has the marital sense to turn a cold shoulder to Heathcliff when he returns in the movie; but in the novel, she all but throws herself at him.
While Linton shows more spirit in the novel, his devotion to Cathy is more puzzling considering the above-mentioned facts. As with Isabella and Heathcliff, Linton has an opportunity to see Cathy's dark side in the novel but still chooses to marry her. The crowning point of Cathy's iniquity is her over-enthusiastic response to Heathcliff's return. This figurative slap in the face to Linton does not dissuade him from loving her, even as he suffers and eventually reacts in anger.
In short, the novel presents a disturbing view of all the characters; and the love between Heathcliff and Cathy is a ruthless force for which everyone suffers. Wyler chooses wisely to temper this force and present a more moderate love story. His characters act in ways that make more sense and with which the general public can identify and sympathize.