We supplemented human muscle with animal muscle. Oxen pulled our plows, horses carried us farther and faster, and wind and water turned our mills. Humans still supplied purpose, direction, and judgment, but we had begun externalizing physical capability. Steam dramatically accelerated the process. Enormous amounts of mechanical power could now be generated without muscles at all, powering factories, locomotives, ships, and mines. Human beings increasingly became operators of power rather than its primary source.
Electricity took the next step. Steam had concentrated power; electricity distributed it. Energy could travel through networks and appear wherever it was needed. Petroleum and the internal-combustion engine distributed mechanical power even further through cars, trucks, tractors, airplanes, and construction equipment. Something profound was happening: capability was becoming detached from the individual person.
Then computers moved this same process from our muscles toward our minds. Computers externalized calculation, memory, information processing, and control. Tasks that once required human cognitive effort could increasingly be performed by machines. Eventually, billions of people carried networked computers in their pockets, providing almost instant access to information, navigation, communication, and computational power. We had entered the age of cognitive industrialization.
