Just as the thought of the ancient world was dominated by philosophy, so was the thought of the Middle Ages dominated by Christian teachings. Even though the sciences began to emerge as a separate entity from philosophy toward the end of the Middle Ages, the social sciences were kept within the limits of philosophy for the next few centuries. The cause of this was because the subject matter of human behavior is so closely related to the subject of theology. Therefore, the social sciences came under the jurisdiction of the Christian church.
Christianity's influence spread across the Roman Empire early in the 4th century. For nearly 1,000 years it overshadowed the search for philosophy and tolerated no opposition. The main philosophers of this era were men of the church. Platonism and Neoplatonism were assimilated and utilized by Christian philosophers and blended with biblical principle.
One of the earliest Christian philosophers was Augustine of Hippo. Others include Boethius, Anselm of Canterbury, Bernard of Clairvaux, and Peter Abelard. Augustine compared Plato's thoughts with God's truths. This divine world of truth is experienced by contemplating God's revelation. Augustine taught that the eternal life of the soul can be confirmed by the soul's possession of eternal truths.
Boethius was a major proponent of Platonist philosophy during the Middle Ages. In 'The Consolation of Philosophy' he stated that eternal ideas are instictive. He believed that people remember certain truths from their soul's previous lives.
St. Anselm, Archbishop of Canterbury, used both belief and logic to find the truth. His most famous writings are his proofs of the existence of God. He used Neoplatonist philosophy as a basis for these proofs.
Bernard of Clairvaux was dubious about using philosophy to justify beliefs. He perfected the principle of love as road to truth.
Abelard borrowed from Socrates a question-and-answer method for teaching theology, published in his book 'Sic et Non' (Yes and No). He was mainly concerned with logic. He taught that the material world is real.
Those theologians who wanted to harmonize the teachings of Christianity with the logical explanations put forth by Aristotle were called the Scholastics, because they were mostly professors at universities. Their philosophies are named Scholasticism. This merging reached its height with the work of Thomas Aquinas. His major work is 'Summa Theologica' (Summary of Doctrine), a question- and-answer approach to theological education that has remained, as yet, unequaled. He posed questions and came up with objections to each himself. He then justified his response with an answer to each objection. He wanted to resolve the conflict between faith and reason by proving that reason should deal with the physical world, but that spiritual world must be accepted by faith. He said that the existence of God is both revealed and provable by reason. His teachings were refuted by John Duns Scotus and William of Ockham.
The Renaissance brought about the end of the Dark Ages. Renaissance scholars were devoted to the ancient Greek and Latin texts, especially those of Plato and Aristotle. Most Renaissance literature consisted of no more than synopses of ancient philosophers. Little new ground was broken until the 17th century.
The dominance of philosophy was still assured, however, by the influence of such figures as Thomas Hobbes, Rene Descartes, Francis Bacon, Immanuel Kant, and John Locke.