The great thinkers of the Middle Ages were largely concerned to adapt and integrate with Christianity the pre-Christian systems of philosophy developed by Aristotle, Plato and the Stoics. This book describes the new systems developed by the medieval philosophers and their followers. It begins with the heirsof St. Augustine: Boëthius, Cassiodorus, St Gregory and St Isidore of Seville. Succeeding chapters - describe the scholars of the Carolingian renaissance of whom the most outstanding were Alcuin and John Scotus Erigena. These are followed by the leaders of the great flowering of Christian though which took place in the late eleventh and twelfth centuries among them St Anselm, Abelard, Hugh of St Victor and the school of Chartres together with the monastic thinkers whose leader was St Bernard of Clairvaux. The thirteenth century and the rise of Scholasticism is also fully described together with the development of the school of Paris St Thomas Aquinas, St Albert the Great, St Bonaventure and Siger of Brabant. The final chapter discusses the nominalism of Ockham and Duns Scotus and the beginnings, in Nicholas of Cusa, of the Platonic thought that was to be characteristic of the Renaissance.