1. Throughout the case, Holmes uses all of his five senses to gather information.
2. Because all of his information is based on his senses, none of his observations can be considered an assumption or a guess.
3. Holmes uses “deduction,” which is a method of stringing little details together to arrive at major conclusions.
4. Holmes approaches the crime exactly as a scientist would, with no preconceived ideas about what the facts mean, and without dismissing any fact as irrelevant.
5. In contrast, Watson’s mind is likely to draw conclusions based on his feelings, which is what many artists do. Therefore, his narrative is full of emotionally charged imagery.
6. One theme of this story is philosophical – how the mind can run away with superstitious belief if reasoning is too tied up with emotions.
7. One psychological theme of the story is how evil seems to be an enduring part of human nature.
8. Another psychological theme is that of loyalty. All of the characters of the story, except for the meanest ones, are highly motivated by their love for others.
9. In this story, the “outside” is violent and a person’s primal fears take over. It is only “inside” the house, man’s civilizing stance against nature that moral rules have force.