A hand’s primary function, Elias Canetti writes in Crowds and Power, is as “a claw to grasp whole branches” while climbing; both hands partner in “grasping” and “letting go.” This is like trade, he argues: “one hand tenaciously holds on to the object with which it seeks to tempt the stranger” while the other “is stretched out in demand.” Trading, then, offers “profound and universal pleasure” as “a translation into nonphysical terms of one of the oldest movement patterns.”

A thirteenth-century Song dynasty text about commerce describes dangers faced by pearl divers, who sometimes fell prey to “huge fishes, dragons, and other sea monsters” that would rip open their stomachs or bite off their feet. A pearl was considered most valuable if perfectly round; the test was “that it will not cease rolling about all day when put on a plate.” To avoid heavy export duties, foreign traders sometimes concealed pearls in canes or umbrella handles.

“Why do you wrong the gods so much?” Greek poet Athenaeus asks a sober party guest in a late second-century work. “You’re no use to the city if you drink water, / because you’re hurting the farmer and the trader; / whereas I increase their income by getting drunk.”

When Arctic traveler Vilhjalmur Stefansson traded with the Inuit of Victoria Island in 1911, he found the metal of their knives to be of curious provenance: Inuit to the east had bought guns from the Hudson Bay Company and traded them westward; the firearms were then traded farther west, eventually reaching the Inuit he’d met—who, having no use for guns, had beat the metal barrels into knife blades.

Herodotus reports that after Cyrus the Great was warned by a Spartan herald not to tread further into Greek lands, the Persian king received a primer on Sparta, including an explanation of an agora, to inform his response. “I have never yet been afraid of any men,” he told the herald, “who have a set place in the middle of their city where they come together to cheat each other.”