Ishmael frequently bemoans the impossibility of examining anything in its entirety, noting that only the surfaces of objects and environments are available to the human observer. On a live whale, for example, only the outer layer presents itself; on a dead whale, it is impossible to determine what constitutes the whale’s skin, or which part—skeleton, blubber, head—offers the best understanding of the entire animal. Moreover, as the whale swims, it hides much of its body underwater, away from the human gaze, and no one knows where it goes or what it does. The sea itself is the greatest frustration in this regard: its depths are mysterious and inaccessible to Ishmael. This motif represents the larger problem of the limitations of human knowledge. Humankind is not all-seeing; we can only observe, and thus only acquire knowledge about, that fraction of entities—both individuals and environments—to which we have access: surfaces.