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 remarks, in an aside, that some might find it strange that Stubb eats the whale’s meat “by its own light” (since the lights in the cabin are lit by whale oil). Ishmael notes that the eating of whale meat is largely out of favor at the time of his writing, though parts of the whale, including its oil and its brains, were once considered delicacies in Europe. But Ishmael states that man eats all kinds of animals, and some (like ox) are eaten with utensils carved from the very bone of that animal—and so the eating of whale meat is not so different from other of man’s carnivorous activities.
Ishmael seems to recognize that whale-meat and whale-fat will seem unpalatable to the common reader. In his comments about the whale being eaten in rooms lit by oil taken from the whale, Ishmael references rules for dining that derive ultimately from the Hebrew Bible—a set of rules known as “kashrut,” or “kosher” principles—which prohibit (among other things) the eating of animals with utensils made from those animals. Ishmael is always pointing out the inconsistencies in the world, how things change and yet how the people of the present act like the customs of the present are totally rational.