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 describes how sailors on other, non-whaling ships often do not have enough oil even to light a very small lamp near their beds—these sailors live lives on the boats of almost “total darkness.” But on a whale-ship, there is so much whale oil that sailors can pick out the finest oil from what comes out of the try-works, and can use it to light themselves as though they used “Aladdin’s lamp.” Ishmael considers this one of the great privileges of sailing on a whale-ship.
Ishmael once again makes an effort to show that whaling, and that shipping on a whaling vessel, is superior to shipping out as a merchant marine, or another kind of sailor. Ishmael clearly delights in reminding himself that whaling is the most noble of man’s occupations on the high seas.