As the novel begins, Kino and Juana live in peace and harmony with their natural surroundings, bound together by their love for their infant son, Coyotito. Their happiness and contentment is expressed in the phrase, the Song of the Family. Once Coyotito is bitten by the scorpion, however, their poverty becomes a crucial factor in their lives and the importance of money is established. They take Coyotito to the doctor in town, but the doctor will not treat the baby because his parents are so poor. If they had had enough money, their baby would have been treated immediately.
The importance of money is also seen in Kino's dreams once he finds the great pearl. He sees a future in which he and Juana can be married in the church and they can provide an education for Coyotito. Kino wants his son to learn how to read so that he will not be powerless in his ignorance. Kino knows that being able to read would protect one from being cheated by dishonest people who can read. Also, Kino dreams of owning a rifle, a means to protect his family. Also, after Kino killed the attacker on the path, he and Juana must run away, but Kino's canoe has been destroyed. If he had had money, he could have purchased a means of escape other than fleeing on foot. Thus, money assumes importance because it can buy medical care, education, and protection for his family.
Money and what it can provide becomes so important to Kino that once he finds the pearl, he becomes obsessed with it. When Juana attempts to throw it back into the sea, he attacks her viciously. He kills a man to keep the pearl, and he and his family lose their peaceful home in the village. Eventually, their son is killed by a stray bullet as they run away. Kino and Juana lose the life they once loved because Kino can't give up his dreams of great wealth.