284	A BRIEF SURVEY OF HUMAN  HISTORY
to a greater equality of classes, the growth of a free peasantry
and of guilds of artisans, and the development of trade and
industry. In the field of politics they were followed by the
rise of the system of Estates, by a growing centralization of
government, and by the appearance of written law and a regular
judicial administration. In the great world of culture, philo-
sophy developed its greatest thinkers after the Crusades and the
connexion with the Arabs which they brought : even mysticism
assumed a scientific character : the study of the ancient lang-
uages grew in extent and fertility : historiography and geogra-
phy acquired a new vigour: a vernacular poetry arose-:
Gothic architecture succeeded: a Romanesque, and a1 finer
taste appeared in sculpture and painting.'1
1.   The Legacy of Islam, p. 51.