Smeling hallucinations

“What was the Depression?”

“Bad economic times in their pure capitalism nation-state,” Aenea said. “Remember, the economy wasn’t really global then, and it depended upon private money institutions called banks, gold reserves, and the value of physical money -actual coins and pieces of paper that were supposed to be worth something. It was all consensual hallucination, of course, and in the 1930s, tha hallucination turned nightmare.”

“Jesus.” I said.

“Precisely.”

The Rise of Endymion, chapter 2 - Dan Simmons