把这一句，留给此刻的你
If a man were living in isolation his income would be literally his product. Make him the monarch and owner of an island, and the fruits that he raises and the clothing that he makes constitute, in themselves, his income. This ceases to be true when trading begins.
如果一个人孤立地生活，他的收入实际上就是他的产品。让他成为一个岛屿的君主和主人，他种植的水果和他制作的衣服本身就构成了他的收入。当交易开始时，这就不成立了。