The author stresses how important it is to look at the nature of civilization, which is made up of the achievements and rules that make human lives different from animal lives. The author says that civilization has two purposes: to protect people from nature and to keep them from hurting each other. In the first stage of civilization, people used tools, learned to control fire, and built homes. These discoveries led to the creation of motor power, transportation, glasses, telescopes, microscopes, cameras, telephones, writing, and homes. The author says that these changes have made it possible for people to improve their own organs and get around the limits of sight and distance.