Money in Robinson Crusoe is something highly valued (and valuable) in society, but utterly useless in nature. Robinson is enticed to go back to sea after making some money on his first voyage to Africa, and the possibility of profit is what drives him to establish a plantation in Brazil. However, once he is stranded on his island, money is completely useless to him. He finds money on his old ship and in the wrecked Spanish vessel, both times remarking that it was of no use to him on the island. In nature, Robinson discovers that things are only worth what they can be used for—he finds food, tools, and water much more valuable than coins. Moreover, money causes greed, from which he is free during his solitary life on the island. Money thus symbolizes the faulty value systems of society, in contrast to the authentic life Robinson discovers on his island. However, Robinson keeps his money on the island and takes it with him when he leaves. Moreover, once he returns to society he needs his fortune in order to establish a life (and repay the loyal widow and the Portuguese captain). While Defoe's novel explores the artificiality or falseness of money's value, it presents it as still necessary for life among society.