One of the best arguments I’ve heard about free trade yet, and it’s not even really about free trade. It’s about civilization.
Every time two people come together and trade, wealth is created. Out of thin air. By magic. Every trade, every bit or work done by every human on the planet increases the complexity and order of the whole, and thus makes it more valuable. This is a rich subject, one we will return to in a following chapter. But for now, suffice it to say that if I, as a member of a hunter tribe, make great spears and crappy baskets, and you, as a gatherer, make beautiful baskets and miserable spears, then when we exchange my spear for your basket both of us walk away richer.