The 12th century was marked by the continuing rebirth of Western European culture. Russell identifies four points of importance:

1. The continued conflict between the empire and the papacy
2. The rise of the cities in northern Italy controlled by the Lombard tribe
3. The Crusades
4. The growth of Scholasticism, a new school of thought that attempted to harmonize Christian doctrine and classical philosophy, particularly that of Aristotle. It is notable that among ancient philosophers it is Aristotle, not Plato, who now holds pride of place—this is a decisive fact that will influence much subsequent thought.

By the 12th century, the Dark Ages were over and the Western intellectual revival was well underway. Abelard, St. Bernard of Clairvaux, and John of Salisbury are among the notable thinkers of this period.

Russell characterizes the 13th century as the “culmination” of the Middle Ages because of its intellectual, artistic/architectural, and political achievements. In the world of philosophy, a synthesis of classical and Christian knowledge came to a climax in the work of the Scholastics. The 13th century brought forth a number of “great men,” including St. Thomas Aquinas, St. Francis of Assisi, Pope Innocent III, and the Holy Roman Emperor Frederick II. In the church, new religious orders were founded, including the Franciscans and Dominicans.