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 comments that it is difficult to know whether the whale’s blubber is its skin or is in fact the layer just below the skin—for there is a “skin’s skin” to a whale, which is a fine transparent layer, that can be dried and used as a “bookmark,” or for decorative purposes. Ishmael notes that the whale’s blubber is much like the blanket or “counterpane” of a sailor—keeping the whale warm even in the northernmost climates of the world, near the North Pole.
At the time, it was considered a genuine mystery how a whale was able to survive in the cold northern seas. Here, Ishmael explains what, to contemporary minds, seems common-sensical—that a whale is protected by a layer of fat, which traps heat inside, keeping the whale’s body at a steady temperature.