Nearly a century later, B.F. Skinner answered Thoreau with the opposite experiment: Walden Two (1948), a novel describing a planned community of a thousand people, engineered not around solitude but around behavioral design — operant conditioning applied, deliberately, to child-rearing, work, and social life itself.

Where Thoreau withdrew from society to perfect himself, Skinner's community is built to perfect itself, collectively, by design.

Two very different utopias, same pond, same word — and, three digits later, the name behind Walden3.