Concerning Dr. Jekyll's Split Personality

In Robert Louis Stevenson's novella "The Strange Case of Dr. Jekyll and Mr. Hyde," Stevenson uses Jekyll and Hyde's split personalities to show that everyone has a monster inside of them that comes out inevitably and in various ways. While I haven't read all of the story yet, I do know the basic gist of why Dr. Jekyll and Mr. Hyde are the way they are based upon their relevance in pop culture. Basically Dr. Jekyll made a potion with the intent of being able to have a split personality that could be mean and do the things he wanted to do but could not. However, it ends up backfiring and he loses control of his transformations. Hyde is described as grotesque and gruesome in appearance. "And still the figure had no face by which he might know it; even in his dreams, it had no face, or one that baffled him and melted before his eyes; and thus it was that there sprang up and grew apace in the lawyer's mind a singularly strong, almost inordinate, curiosity to behold the features of the real Mr. Hyde." (p. 2246, I don't know what page in the regular editions). With this Stevenson is not only saying that our inner desires are disgusting and gruesome, but also that humanity is fascinated by evil. Utterson is amazed by Hyde's evil and a sort of curiosity is fostered by it. Once again there is also a sort of Dr. Faustus complex on display here. Through Dr. Jekyll trying to be more than he is and create a split personality for himself, he does more harm to himself and those around him than he does good. He's overambitious, and while his intentions were good, they ultimately lead to his downfall.