Final answer:
In High School English, Herbert's incredulity towards the sergeant-major's tale suggests disbelief in the story's extraordinary content, a common trope in literature.
Step-by-step explanation:
The question indicates the student is dealing with a literature review or textual analysis, typically a component of an English class in High School. When Herbert was described as 'incredulous' after hearing the sergeant-major's tale, it implies that he found the story so unbelievable or extraordinary that he had difficulty accepting it as true.
Alternatively, this statement could relate to the theme of supernatural or folklore within literature, as werewolves are a common motif in such stories. In this context, Herbert's incredulity could be tied to his rational mindset clashing with the fantastical elements of the tale he's being told. The passage exemplifies how authors use character reactions to emphasize the implausibility or horror of certain narratives, enhancing the reader's engagement with the story's thematic content.