Ishmael attempts to describe the large and powerful tail of the sperm whale, stating that its grace and beauty go hand in hand with its enormous size—sometimes over twenty feet in length. But Ishmael finds that he doesn't have the words “adequate” to describe this particular body part, which he finds the most “sublime” feature of a whale’s anatomy. And Ishmael despairs that, if he cannot describe the tail of the whale, he might not in fact be able to describe its “face,” or certainly not what the whale appears to be thinking—its motivations, its desires. Ishmael closes the chapter on this note of uncertainty.
The “sublime” is of key importance to Ishmael, and to the novel as a whole. Sublimity is a difficult concept to define, but it appears, here, to describe a stage of aesthetic appreciation beyond simple beauty, something so magisterial that it awes because it is beyond human comprehension. Although sperm whales can be beautiful, their power, their hunger, their head-shapes, and even the way they swim appear to have a specific gravity, or forcefulness. This impression of great strength contributes to the whale’s sublime character—its power over human beings.