To build a folly is essentially to do something a second time, something at an inopportune moment. That something is always the memory of something forgotten, about which we can paradoxically say "There it is again."
Follies were misunderstood, purposeless constructions. They were often only small, extravagant gestures in a garden, easily whisking off the imagination to distant lands, a sort of time capsule built to awaken the memory and induce surprise in passers-by. They marked locations, organized secondary paths in a park, or simply predicted the arrival of better times—a demarcation, a sacred spot, a mysterious trail, a hill whose tragic rocky nature begged for a tower, a party, or the arrival of summer.
“It is demonstrably true that things cannot be other than as they are. For, everything having been made for a purpose, everything is necessarily for the best purpose.” — Professor Pangloss
Local Code was Sorkin’s attempt to design a whole city from scratch—with one big twist. The whole thing had been written as if it were the byzantine, nearly impossible to follow codes and regulations for an entire, hypothetical metropolis. The effect is like stumbling upon the source code for SimCity. Sorkin’s exhaustively made point was that, if you know everything about a given metropolis, from its plumbing standards to its parking requirements, its sewer capacity to the borders of its school districts, then you could more or less accurately imagine the future form of that city from the ground up.