How does Stevenson explore the possibilities of the split between “good” and “evil” in “strange case of Dr Jekyll & Mr Hyde”?

Robert Louis Stevenson brings the possibility of another side of person to life in his tale of “strange Dr. Jekyll and Mr. Hyde”. He uses three narrators in the book to describe the tale of Dr. Jekyll, a respected, very "good" doctor who creates or as some would better describe it as bringing out the more Neolithic man in side him, in the form of Mr. Hyde. The most puzzling part of the book is that the full details of the story are not revealed until the very end of the novel. Until we learn the ultimate truth from Dr. Jekyll's confession, we try to decipher (along with the main characters) who Mr. Hyde is ... and how he relates to Dr. Jekyll.

At the end of the book, we discover that Dr. Jekyll had explored for some time that there are two natures in him self. For many years, he has repressed the more man like side. After lengthy thought, he came to the conclusion: "If each, I told myself, could but be housed in separate identities, life would be relieved of all that was unbear...