and wealth by means of its creed. The lay rulers, who were in frequent conflict with it, were
defeated because the great majority of the population, including most of the lay rulers themselves,
were profoundly convinced of the truth of the Catholic faith. There were traditions, Roman and
Germanic, against which the Church had to fight. The Roman tradition was strongest in Italy,
especially among lawyers; the German tradition was strongest in the feudal aristocracy that arose
out of the barbarian conquest. But for many centuries neither of these traditions proved strong
enough to generate a successful opposition to the Church; and this was largely due to the fact that
they were not embodied in any adequate philosophy.
A history of thought, such as that upon which we are engaged, is unavoidably one-sided in dealing
with the Middle Ages. With very few exceptions, all the men of this period who contributed to the
intellectual life of their time were churchmen. The laity in the Middle Ages slowly built up a
vigorous political and economic system, but their activities were in a sense blind. There was, in
the later Middle Ages, an important lay literature, very different from that of the Church; in a
general history, this literature would demand more consideration than is called for in a history of
philosophic thought. It is not until we come to Dante that we find a layman writing with full
knowledge of the ecclesiastical philosophy of his time. Until the fourteenth century, ecclesiastics
have a virtual monopoly of philosophy, and philosophy, accordingly, is written from the
standpoint of the Church. For this reason, medieval thought cannot be made intelligible without a
fairly extensive account of the growth of ecclesiastical institutions, and especially of the papacy.
The medieval world, as contrasted with the world of antiquity, is characterized by various forms
of dualism. There is the dualism of clergy and laity, the dualism of Latin and Teuton, the dualism
of the kingdom of God and the kingdoms of this world, the dualism of the spirit and the flesh. All
these are exemplified in the dualism of Pope and Emperor. The dualism of Latin and Teuton is an
outcome of the barbarian invasion, but the others have older sources. The relations of clergy and
laity, for the Middle Ages, were to be modelled on the relations of Samuel and Saul; the demand
for the supremacy of the clergy arose out of the period of Arian or semi-Arian emperors and kings.
The dualism of the kingdom of God and the kingdoms of this