Themes

The beast in man - Robert Louis Stevenson wrote this novel during his period in Bournemouth, 1884—7. The setting  appears to be Victorian London yet, as many have noted, he clearly has Edinburgh in mind with, like Jekyll, its twin identities, the prosperous and respectable New Town and the Old Town of poverty and desperation. Much of the novel takes place with the city at night as a backcloth. The characters always seem to be coming and going either late at night or in the early hours of the morning. The meagre light comes from the many flickering street lamps which swing in the wind and the pale moon which is often hidden by low cloud and fog.

'The double' - Dr Jekyll and Mr Hyde was not the only story which expressed Stevenson's fascination with the dual personality of man. In two other works, the short story 'Markheim' and the play Deacon Brodie there are characters who also lead double lives. In 1859 Charles Darwin, in On the Origin of Species, had thrust into the Victorian consciousness his unpalatable theory that mankind was, in fact, descended from apes. Stevenson would have been well aware of the controversy which grew from these ideas and sought a vehicle on which to launch his ideas about 'the beast in man' and the attempt to hide, if not to subdue, animal passions. In Stevenson's words Dr Jekyll and Mr Hyde is about 'that damned old business of the war in the members' and because of the strictures of religion and conventional morality, men were forced to hide their secret desires in their public lives and indulge them at night in the darker, seedier parts of the city.
Repressed sexual desires - Those who were especially prey to these animal passions were men who believed that they could exist perfectly well 'without the aid of women', men like the characters in Stevenson's novel - Enfield (where exactly had he been to come home 'about three o'clock of a black winter morning'?), Utterson, Lanyon and Jekyll. There are repeated references to locked doors and cabinets and secret chambers reinforcing the idea that the beast must not only be hidden but imprisoned. It is clear that Dr Jekyll and Mr Hyde is, at least partly, about sexual repression, although the subject of sex itself is never explicitly mentioned in the text. 

Contemporary psychology - Interestingly, at the same time as Stevenson was writing his novel, the French neurologist Charcot was using hypnosis as a means of revealing hidden aspects of the human personality. One of his public displays was witnessed by Sigmund Freud whose Interpretation of Dreams, to be published in 1901, argued that dreams were an expression of repressed sexual desires. Published in 1886 Krafft-Ebing's Psychopathia Sexualis attempted to analyse the war between man's basic, beastlike instincts and the need to conform to conventional moral standards and presented a series of case studies of sexual perversion. Although Stevenson may not have read this study, it does serve to illustrate some of the intellectual and psychological concerns of the time. The fact that he presents part of his novel as a casebook provides another link with contemporary thinking.
The Beast of Whitechapel - It is interesting to note that the notorious 'Jack the Ripper' crimes, in which five prostitutes were brutally murdered and mutilated in Whitechapel in the East End of London, took place within two years of the publication of Stevenson's novel and at the same time as a dramatised version was running in the West End.

Art mirrors life - At the time, these events and Dr Jekyll and Mr Hyde became confused in the public consciousness. People were not really sure which had come first and some of those who did know accused Stevenson of putting ideas in the murderer's mind. One journalist writing at the time concluded that, 'There seems to be a tolerably realistic impersonation of Mr Hyde at large in Whitechapel'. What the murders did reveal, however, was the land of world that Stevenson was well aware of in the Old Town of his native Edinburgh, a world of poverty and despair where the rich and powerful would prey on the weak and defenceless.