So she said banteringly: "What's the unit of exchange in this different world of yours?"
He did not hesitate. "The tear."
"It isn't fair," she objected. "Some people have to work very hard for a tear. Others can have them just for thinking."
"What system of exchange is fair?" he cried, and his voice sounded as if he were really drunk. "And whoever invented the concept of fairness, anyway? Isn't everything easier if you simply get rid of the idea of justice altogether? You think the quantity of pleasure, the degree of suffering is constant among all men? It somehow comes out in the end? You think that? If it comes out even it's only because the final sum is zero."

The Sheltering Sky (1949)