LitCharts assigns a color and icon to each theme in Moby-Dick, which you can use to track the themes throughout the work.
Limits of Knowledge
Fate and Free Will
Nature and Man
Race, Fellowship, and Enslavement
Madness
Religion
Summary
Analysis
Ishmael adds, however, that he has, on occasion, seen some accurate sketches, paintings, and engravings of whales, and that these happen to be done by French artists most frequently, especially by a man named Garnery. Ishmael concludes that Garnery was either a whaleman himself, or was “tutored” by a sailor at some point. Garnery’s paintings are particularly good at depicting the sperm and right whales as they are being hunted by whale boats on the high seas.
Melville clearly spent a great deal of time researching depictions of whales from across various cultures, and in different time periods. Ishmael has discussed whale science and books about whales, here in his testimony that the best pictures of whales are made by those tutors by actual whalemen he begins to tout the value of the knowledge gained by experience.