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
Today's real world of technology is characterized by the dominance of prescriptive technologies.
The temptation to design more or less everything according to prescriptive and broken-up technologies is so strong that it is even applied to those tasks that should be conducted in a holistic way. Any tasks that require caring, whether for people or nature, any tasks that require immediate feedback and adjustment, are best done holistically. Such tasks cannot be planed, coordinated, and controlled the way prescriptive tasks must be.
Prescriptive technologies eliminate the occasions for decision-making and judgment in general and especially for the making of principled decisions. Any goal of the technology is incorporated a priori in the design and is not negotiable.