But it does not enter into the plan or the object of this work to carry such observations further.[217] After having spoken of the heroic deeds and of all that was wonderful in the first crusade, I will turn my attention to the immediate effects it produced upon Europe and Asia. We are sufficiently well acquainted with the evils by which it was followed; great disasters are the familiar subjects of history, but the slow and almost insensible progress of the good that may result from a great revolution, is much less easily perceived. The first result of this crusade was to carry terror among the Mussulman nations, and to place it out of their power to undertake for a length of time any warlike enterprises against the West. Thanks to the victories of the Crusaders, the Greek empire extended its limits, and Constantinople, which was the road to the West for the Saracens, was rendered safe from their attacks. In this distant expedition Europe lost the flower of its population, but it was not, as Asia was, the theatre of a bloody and disastrous war; of a war in which nothing was respected, in which provinces and cities were, by turns, ravaged by the conquerors and the conquered. Whilst the warriors of Europe were shedding their blood on the plains of the East, the West remained in profound peace. Among Christian nations it was then considered a crime to take up arms for any other cause than that of Jesus Christ. This opinion contributed greatly to check the frightful brigandage that had prevailed, and to increase respect for _the truce of God_, which was, in the middle ages, the germ or the signal of the best institutions. Whatever were the reverses of the crusades, they were less deplorable than the civil wars and the scourges of feudal anarchy that had so long ravaged all the countries of the West. This first crusade produced other advantages to Europe.[218] The East, by the holy war, was in some sort laid open to the West, which, before, was but little acquainted with it; the Mediterranean became more frequented by European vessels, navigation made some progress, and commerce, particularly that of the Pisans and Genoese, must have been increased and enriched by the foundation of the kingdom of Jerusalem. A great part, it is true, of the gold and silver of Europe was carried into Asia by the Crusaders; but these treasures, heaped up and concealed by avarice and fear, had been long abstracted from circulation; the gold which was not carried away by the Crusaders circulated more freely, and Europe, with a less quantity of money, appeared all at once more rich than it had ever been.