Doyle used the idea from a quote in his text as the basis for the overarching structure of his book A Study in Scarlet. He presented the importance of making unbiased judgments in the first part of the book but proceeded to test the reader’s observance of this idea. “’It is a capital mistake to theorize before you have all the evidence. It biases the judgement’” (27). When Sherlock Holmes says this, he is stating it in a matter-of-fact sort of way, implying that this should be obvious. The use of the word “capital” shows that doing this is among the worst mistakes that can be made. This is shown through the fact that capital crimes are the worst crimes that can be committed and are punishable by death. The strong emphasis on the phrase “biases the judgement” is very reasonable because as scientists, preventing opinion from affecting their conclusions is crucial. Although this quote is about not having a preconceived notion of the crime, it also applies to not judging a person before you know the details of their life. This is arguably the main theme of the book because Doyle organized the book in a way that the reader heard the terrible crimes the “criminal” committed and judged the criminal as a terrible person; then Doyle showed the events that caused the “criminal” to pursue and murder the men. In the second part of the book, it is revealed that the criminal was actually a good person and that the reader made an incorrect judgment because the reader did not follow the advice of Sherlock.