I take it that by refering to "chapter 26.3" you mean the third paragraph of chapter 26. This chapter introduces us to Starbuck, the chief mate of the Pequod, and the kind of character that he is. The third paragraph gives us a very interesting insight into his motivations and what drives him as an individual:
Starbuck was no crusader after perils; in him courage was not a sentiment; but a thing simply useful to him, and always at hand upon all mortally practical occasions. Besides, he thought, perhaps, that in this business of whaling, courage was one of the great staple outfits of the ship, like her beef and her bread, and not to be foolishly wasted. Wherefore he had no fancy for lowering for whales after sun-down; nor for persisting in fighting a fish that too much persisted in fighting him. For, thought Starbuck, I am here in this critical ocean to kill whales for my living, and not to be killed by them for theirs; and that hundreds of men had been so killed Starbuck well knew. What doom was his own father's? Where, in the bottomless deeps, could he find the torn limbs of his brother?
If we remember that this novel is meant to be an allegory of life and that the task of whaling is therefore meant to represent the various labours that we engage in, Starbuck's character is meant to present one way of living our lives. Note Starbuck's attitude towards courage in particular. The quote says that courage is "not to be wasted." Therefore, whilst Starbuck was a very hard-working individual, at the same time he was against taking foolish risks to kill whales and refuses to risk his life. For, Starbuck reasons, he is at sea to kill whales, not to be killed by them. The nameless fate of all those who have squandered courage and died as a result is refered to at the end. This passage therefore presents us with a way of living our lives that is not reckless.