In the early 1970s, the science fiction writer Robert Heinlein issued a dictum, often quoted since, that “specialization is for insects.” Truly capable human beings, he wrote, should be able to do almost anything from changing a diaper to commanding a warship. It is a noble sentiment that celebrates human adaptability and resilience, but it’s wrong. While there was once a time when every homesteader lumbered his own trees and built his own house, this not only was inefficient, but produced only rudimentary housing.
