Literary genres which critics have applied as a framework for interpreting the novel include religious allegory, fable, detective story, sensation fiction, doppelgänger literature, Scottish devil tales and gothic novel. Dr Jekyll and Mr Hyde has been the influence for The Hulk, Two-Face and the general superhero genre for the story's ties to a double life.
This story represents a concept in Victorian culture, that of the inner conflict of humanity's sense of good and evil. In particular the novella has been interpreted as an examination of the duality of human nature (that good and evil exists in all), and that the failure to accept this tension (to accept the evil or shadow side) results in the evil being projected onto others. Paradoxically in this argument, evil is actually committed in an effort to extinguish the perceived evil that has been projected onto the innocent victims. In Freudian theory the thoughts and desires banished to the unconscious mind motivate the behaviour of the conscious mind. If someone banishes all evil to the unconscious mind in an attempt to be wholly and completely good, it can result in the development of a Mr Hyde-type aspect to that person's character. This failure to accept the tension of duality is related to Christian theology, where Satan's fall from Heaven is due to his refusal to accept that he is a created being (that he has a dual nature) and is not God. This idea is suggested when Hyde says to Lanyon, shortly before drinking the famous potion – "...and your sight shall be blasted by a prodigy to stagger the unbelief of Satan." This is why in Christianity, pride (to consider oneself as without sin or without evil) is the greatest sin, as it is the precursor to evil itself; it also explains the Christian concept of evil hiding in the light.
Various direct influences have been suggested for Stevenson's interest in the mental condition that separates the sinful from moral self. In his discussion of the novel, Vladimir Nabokov argues that the "good versus evil" view of the novel is misleading, as Jekyll himself is not, by Victorian standards, a morally good person.
One popular interpretation is the "civilized versus animalistic" approach. Other readers have argued even further that the split between Dr Jekyll and Mr Hyde represents the civilised and the animalistic version of the same person. The description of Hyde as an almost prehuman creature and his actions that occur without thought, suggests that Hyde is more animal than man. Dr Jekyll on the other hand, can be seen as existing in a constant state of repression, with the only thing controlling his urges being the possible consequences imposed by civilised society.
Another common interpretation sees the novella's duality as representative of Scotland and the Scottish character. On this reading the duality represents the national and linguistic dualities inherent in Scotland's relationship with the wider Britain and the English language, respectively, and also the repressive effects of the Church of Scotland on the Scottish character. A further parallel is also drawn with the city of Edinburgh itself, Stevenson's birthplace, which consists of two distinct parts: the old medieval section historically inhabited by the city's poor, where the dark crowded slums were rife with all types of crime, and the modern Georgian area of wide spacious streets representing respectability.
The novella has also been noted as "one of the best guidebooks of the Victorian era" because of its piercing description of the fundamental dichotomy of the 19th century "outward respectability and inward lust," as this period had a tendency for social hypocrisy.