what points does ishmael express doubts with in the story of jonah

Chapter Eighty-Three: Jonah Historically Regarded:

Many Nantucket whalers distrust the story of Jonah. One Sag-Harbor whaleman cites his chief reason for doubting the story to be the pictorial representation of Jonah's whale with two spouts, and this type of whale is not large enough to swallow a person. Another reason why Sag-Harbor doubts the story is the whale's gastric juices, but the whale that swallowed Jonah may have been dead at the time. Ishmael calls Sag-Harbor's arguments foolish and lacking reason.

The scholastic and the epic mythological tones of Moby Dick collide during this chapter, in which Ishmael attempts to analyze the Biblical tale of Jonah and the Whale from a scientific perspective, justifying this Biblical tale by attempting to fit it into a plausible mode of intellectual study. The effect of this is jarring and somewhat tonally inconsistent, in contrast to the normally smooth flow of tones throughout the chapters of Moby Dick. While Melville can move effortlessly from the different styles that he employs throughout the chapters, within this individual chapter the move is strained.