How does the novel explore the conflict between rationalism and the occult?
Arguably, this novel's case interests Holmes because it seems to so strongly suggest an occult explanation. Thus, it poses him a challenge: find a rational explanation for what would otherwise be attributed to the supernatural. Throughout the story, characters battle these two opposing forces. The hound is representative of a superstitious belief in evil. Even men of science - Dr. Mortimer and Dr. Watson - somewhat accept the occult explanations, both because they can find no scientific clues to the contrary and because the atmosphere of the moor evokes such conjectures. It is telling that Holmes, by remaining firmly convinced that there must be a rational explanation, eventually discovers that explanation, and even reveals what Stapleton did to make the hound seem so other-worldly. Thus, the novel overall reveals how humans have a tendency towards supernatural explanations, but suggests that we can remain firmly embedded in the rational if we have the strength of will to do so.