Duality of Human Nature

I believe that The Strange Case of Dr. Jekyll and Mr. Hyde is the most relevant example of the duality in human nature. Much like the politicians of today, Dr. Jekyll has two sides. Unlike people today though, Dr. Jekyll tries  keeps his two lives completely separate by making them literally two separate people. Jekyll emphasizes that man is "not one, but two", there is a good side and a bad side and only by separating the two can each part become purely it's own rather than fighting for dominance within the human soul. Much like in Oscar Wilde's A Picture of Dorian Gray, Hyde is the pure representation of Jekyll's evil like Dorian's portrait is of him. Once distinction is that while Jekyll has completely removed his evil from him and forced it into the persona of Hyde, Dorian's evil still resides within him. Dorian's soul is still to half's fighting against each other with the protist being merely a reflection of his soul. Each bit of evil that Dorian partakes in causes some sort of blemish on  his portrait. As Dorian continues to partake in evil, his portrait becomes more hideous, just like Dorian's corrupted soul. This is shown as well in Hyde. As Hyde is already a reflection of pure evil, he does not gradually become more and more hideous, he begins that way. He is pure evil and such is reflected in his looks much as Dorian's supposed 'goodness' is reflected in his more handsome features.