The Romans thought of themselves as the chosen people, yet they built the greatest army on Earth by recruiting warriors from any background.
Although prefabrication has a long history - the ancient Romans shipped pre-cut stone columns, pediments, and other architectural elements to their colonies in North Africa, where the numbered parts were reassembled into temples - the idea took on a new impetus with the technological advances of the Industrial Revolution.
The idea that women are innately gentle is a fantasy, and a historically recent one. Kali, the Hindu goddess of destruction, is depicted as wreathed in male human skulls; the cruel entertainments of the Romans drew audiences as female as they were male; Boudicca led her British troops bloodily into battle.
The Romans were not inventors of the supporting arch, but its extended use in vaults and intersecting barrel shapes and domes is theirs.
Perhaps Western civilization is in a post-decline phase, or maybe the decline is just taking a really long time, like the Roman Empire's did. The Romans had gladiators and Christian-hungry lions and that sort of thing. We have MTV.