“O drug!” said I aloud, “what art thou good for? Thou art not worth to me, no, not the taking off of the ground; one of those knives is worth all this heap; I have no manner of use for thee; e’en remain where thou art and go to the bottom as a creature whose life is not worth saving.” However, upon second thoughts, I took it away. . . .

      In this quotation , the drugs mean money . Robinson Crusoe was all alone in this island . When he went to the ship, he found some thing that he need to him such as food, water ,weapon... By this way he found money ... But the last thing he need was ''money'' in this island because he did not have anything to buy this money or there was no shopping center .Therefore he noticed the knife was more useful for him than money . He could not use the money but with the help of money, he could protect himself , chop the fruit or some vegetables , anywhere else in the island. In his normal life 'money' was one of the important things ,but he saw the useless of money .

    Finally he took the money . Why did he take the money?  This question has a lot of answers . First of all, he had a hope to get rid of this island. If he got off there , he would have need this money . Perhaps this hope was the only thing to keep him alive during the years. Secondly ,  we can see how expedient person he was or how much importance he gave the money. He know that he did not need the money but he took it. This shows his expediency.