Steven Pinker in Greater Good:
Ancient texts reveal a stunning lack of regard for human life. In the Bible, the supposed source of all our moral values, the Hebrews are urged by God to slaughter every last resident of an invaded city. “Go and completely destroy those wicked people, the Amalekites,” reads a typical passage in the book of Samuel. “Make war on them until you have wiped them out.” The Bible also prescribes death by stoning as the penalty for a long list of nonviolent infractions, including idolatry, blasphemy, homosexuality, adultery, disrespecting one’s parents, and picking up sticks on the Sabbath. The Hebrews, of course, were no more murderous than other tribes; one also finds frequent boasts of torture and genocide in the early histories of the Hindus, Christians, Muslims, and Chinese.
But from the Middle Ages to modern times, we can see a steady reduction in socially sanctioned forms of violence. Many conventional histories reveal that mutilation and torture were routine forms of punishment for infractions that today would result in a fine. In Europe before the Enlightenment, crimes like shoplifting or blocking the king’s driveway with your oxcart might have resulted in your tongue being cut out, your hands being chopped off, and so on. Many of these punishments were administered publicly, and cruelty was a popular form of entertainment.
We also have very good statistics for the history of one-on-one murder, because for centuries many European municipalities have recorded causes of death. When the criminologist Manuel Eisner scoured the records of every village, city, county, and nation he could find, he discovered that homicide rates in Europe had declined from 100 killings per 100,000 people per year in the Middle Ages to less than one killing per 100,000 people in modern Europe.