1100-1400: The most devout Christians, the monks and nuns, lead lives of quiet piety, cloistered away from the cares of the world.

1450-1600: Pious men begin to realize that piety can be practiced here on earth, so many humanist scholars, who are at the same time highly religious, invest themselves in making society a better place to be.

Today: Religious men and women devote themselves to the betterment of the underprivileged here on earth as do the humanists.

1100-1400: In the west, Christianity is a common aspect of life. People of other religions are sometimes treated as strangers, infidels, or unbelievers and are persecuted.

1450-1600: As Christianity splits into Catholicism and Protestantism, religious persecution continues, now between the two branches. Persecution of Jews, Muslims, and people who practice neither Catholicism nor Protestantism is also rampant.

Today: Religious tolerance is a hallmark of a liberal...