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
Fedallah and Ahab stay awake that night, watching the dying whale as the boat is hooked to it, and waiting until the next day, when they can drag it back to the Pequod. Ahab falls briefly asleep and tells Fedallah he has had a dream of his own death, and Fedallah reminds Ahab of a prophecy that has not yet been told to the reader: that before Ahab will be allowed to die, he will see “two hearses,” the first one “not made by human hand,” and the second “made of wood from America.” Fedallah also tells Ahab that “hemp” will cause his demise. Ahab takes this to mean that he will be hanged for some unnamed crime, but Fedallah does not corroborate this interpretation of the prophecy, and they are “silent” until the next day.
The final of the novel’s prophecies. It's not yet clear whether this prophecy will prove to be accurate in hindsight. Yet Ahab is confident in his interpretation of the prophecy—an interpretation that convinces him of exactly what he wants to believe, that he will survive. Prophecies are as subject to the way men see the world (through the lens of themselves) as everything else can be, whether omen or doubloon.