Chinese Taoist philosophers Zhuangzi and Hui Shi took a walk on a bridge over the Hao River in the fourth century bc. “The minnows swim about so freely,” said Zhuangzi; “such is the happiness of fish.” Hui Shi responded, “You are not a fish, so whence do you know the happiness of fish?” “You are not I,” Zhuangzi replied, “so whence do you know I don’t know the happiness of fish?”

“It was rejected because it was so simple and looked like too much fun,” Kurt Vonnegut wrote of his failed 1965 master’s thesis in anthropology, in which he argued that the plots of stories, when graphed, conform to a set of standard patterns. “The apathy of the University of Chicago is repulsive to me. They can take a flying fuck at the moooooooooooooooon.”

A 2018 study run at Buttercups Sanctuary in Kent, England, found that goats are sensitive to human emotions and strongly prefer to sniff smiling, happy faces rather than frowning ones.

“In 1931, when Brave New World was being written, I was convinced that there was still plenty of time,” wrote Aldous Huxley in 1958. He’d thought “the completely organized society, the scientific caste system, the abolition of free will by methodical conditioning, the servitude made acceptable by regular doses of chemically induced happiness” were all far off, but now he had come to feel “a good deal less optimistic.” It seemed his prophecies were “coming true much sooner than I thought they would.”

President Herbert Hoover once praised a group of PR professionals. “You have taken over the job of creating desire,” he said, “and have transformed people into constantly moving happiness machines—machines which have become the key to economic progress.” It was 1928; the Great Depression began the following year.