Dualism to Robert Louis Stevenson was a concept he cared greatly about and even as a child, he was told about the ideas of good and evil. Growing up in a heavily religious family, his nanny would tell him that there are only two types of people in the world- good and bad. However Stevenson later questioned that idea and focused more on the idea of dualism and a split personality- the concept that every person is not just good or bad, but has a mixture of both in them.
Even before being introduced to Dr Jekyll or Mr Hyde, the ideas of dualism are already being played out. For example the use of setting description connotes a hidden dualism, The shop-fronts stood along that thoroughfare with an air of invitation like rows of smiling saleswoman. Stevensons use of a simile connotes that this area of London is very respectable and its inhabitants are very reputable people. This would be typical in the Victorian era as morality was very highly thought of and the successful area would have been run by those who held strong moral values. Stevenson then goes on to describe a door located close to the respectable area the door which was equipped with neither a bell nor knocker, was blistered and disdained. The door and the building around it are very contrasting to the previous sight. Blistered and disdained conveys that the door was not well looked after and the building obviously didn't belong to someone who had high moral standards. With neither a bell nor knocker connotes that it is very uninviting and unwelcoming, and also connotes decay and negligence regarding its condition. The contrasting locations being so close together is a reference to dualism, which Stevenson would have been exposed to a lot as a child. Growing up in Edinburgh Stevenson would have seen the two contrasting areas of the New and Old Town. This was another example of dualism as Edinburgh was a city with two very different parts.