=The Conflict between the Two Civilizations.――The Crusades.[60]= The rivalry between the two civilizations became intensified into an open conflict about the year 1100. Up to the year 1000 the Mohammedan leaders were Arabians, but in the eleventh century these Arabians were conquered by tribes of Turks or Mongolians from the north of Asia. These became converted to Mohammedanism, but they had no love for culture nor reverence for the places in Palestine, which were sacred alike to the Christian and the Arab. From the fourth to the twelfth century the pilgrimages of the Christians, individually or in multitudes, largely increased, but in the eleventh century the new race of Mohammedan Turks made the access to Jerusalem more difficult. They began to subject the pilgrims to cruelties, so that the Christian was beginning to find the door of his Holy Land closed to him. Then did Platonic Christianity rush to the rescue of those sacred places that symbolized its ideals. This onslaught upon the Mohammedans came in a series of surges, traditionally spoken of as the eight Crusades.[61] The Crusades resulted quite contrary to the expectations of the church, for the Crusaders failed in permanently recapturing Jerusalem. But the Crusades accomplished the unexpected thing――they awakened Europe. The effect of the Crusades upon Europe was far greater than upon the Orient. The results may be enumerated as follows:―― 1. The dormant European intellect was shaken up by contact with the heathen, whom the Europeans had previously despised, but whom they found to be their superiors. 2. A new national rivalry was aroused among the Christian soldiers. This national spirit was helped negatively by the losses among the feudal lords. 3. Commercial activity was given an immense impulse. A new social class was formed, which allied itself with the kings against the feudal lords. Trade was opened with the East, revealing new luxuries and new needs. Venice, Pisa, and Genoa, and in a secondary way also the German, French, and English towns, became prosperous commercial centres. 4. The power of the Latin church was extended. 5. _The works of Aristotle were introduced in translations direct from the original Greek._ In the fourth Crusade Constantinople was captured by the Crusaders (1204), and in this way the treasures of the Greeks were opened to the western scholars. The complete works of Aristotle were introduced into western Europe at a time when Aristotle was being interpreted as a pantheist by the Arabian commentators.