Final answer:
The passage from Stevenson's novel discussed topics related to gut instincts, evil, and murder, focusing on the characters' reactions to a foreboding presence and the consequences of a dark association.
Step-by-step explanation:
The passage from Robert Louis Stevenson's The Strange Case of Dr. Jekyll and Mr. Hyde discusses the topics of gut instincts, evil, and murder. These three primary concepts are part of the dialogue between the characters, expressing a visceral reaction to a gentleman's strange aura, a premonition of evil, and fears around murder. The mood and language used in the passage evoke a chilling atmosphere and hint at the darker elements of the human psyche and morality.