In one respect I can indeed perceive the accidental operation of the crusades, not so much in producing a benefit as in removing an evil.

The larger portion of the inhabitants of Europe was chained to the soil, without freedom, or property, or knowledge; and the two orders of ecclesiastics and nobles, whose numbers were comparatively small, alone deserved the name of citizens and men.

This oppressive system was supported by the arts of the clergy and the swords of the barons.

The authority of the priests operated in the darker ages as a salutary antidote: they prevented the total extinction of letters, mitigated the fierceness of the times, sheltered the poor and defenceless, and preserved or revived the peace and order of civil society.

But the independence, rapine, and discord of the feudal lords were unmixed with any semblance of good; and every hope of industry and improvement was crushed by the iron weight of the martial aristocracy.
Among the causes that undermined that Gothic edifice, a conspicuous place must be allowed to the crusades.