The map and the clock belong to the fourth category, which might best be called, to borrow a term used in slightly different senses by the social anthropologist Jack Goody and the sociologist Daniel Bell, “intellectual technologies.” These include all the tools we use to extend or support our mental powers—to find and classify information, to formulate and articulate ideas, to share know-how and knowledge, to take measurements and perform calculations, to expand the capacity of our memory.
