Key Themes in Chapter One of The Strange Case of Dr Jekyll and Mr Hyde

Enfield's account of Hyde callously trampling the young girl makes Hyde appear immediately unnatural. This unnaturalness is hinted at again when Enfield says that there was something deeply unpleasant about Hyde but he couldn't say what:

'There is something wrong with his appearance; something displeasing, something downright detestable. I never saw a man I so disliked, and yet I scarce know why' (p. 6). This feeling is shared by other characters; it indicates a subconscious awareness that Hyde is somehow unnaturally evil.

Enfield is not alone in feeling like this about Hyde. He says that the doctor turned 'sick and white with the desire to kill him' (p. 4) and he had to keep the women from attacking Hyde because they were 'as wild as harpies' (p. 4). 

The doctor who attends the trampled girl is the first medical professional to appear in the novella, but both Lanyon and Jekyll are also medical doctors. The term 'Sawbones' (p. 4) that Enfield uses is slightly disparaging. It comes from a time when doctors could do little to treat sick or injured people and the type of crude surgery that took place - such as amputating crushed or diseased limbs - was carried out by people with little medical training They were called 'Sawbones' because they used saws to cut through bones during amputations. Enfield tells us that this doctor spoke with an Edinburgh accent, which suggests he trained at the famous and respected medical school in Edinburgh. This would make him more than a Sawbones', so Enfield is showing disdain or lack of respect in using the term. As Stevenson grew up in Edinburgh, he would have been well aware of the good reputation of doctors trained there. 

Enfield calls the house with the door 'Blackmail House' (p. 5) because he assumes the only reason someone like Jekyll would give money to a person like Hyde is that he is being blackmailed. He describes the person who wrote the cheque (Jekyll) as 'the very pink of the properties, celebrated too' (p. 5) - meaning someone who is respected and beyond suspicion. Utterson accepts Enfield's assumption and later acts on it. As readers, we take the same view, having no reason to challenge it.

As it turns out, Enfield is wrong about the blackmail. This is  the first of many mistakes and wrong assumptions in the course of the novella. They help Stevenson to maintain suspense and surprise. 

It's important to be able to write about the way Enfield behave interacts with Utterson, the only character we see him with. En seems to be an unlikely friend for Utterson. Enfield is a 'well-known man about town' (p. 2), while Utterson is cold and dry. Although the pair value and look forward to their weekly walks, they talk little and seem relieved if they meet someone else.

What he says reveals more about his character. Enfield doesn't like to ask questions. He says, 'You start a question, and it's like starting a stone. You sit quietly on the top of the hill; and away the stones go, starting with others' (p. 5). This suggests that he prefers to be in control and doesn't like unpredictable consequences.