WRITING some 50 years ago, Archduke Otto Hapsburg, the last pretender to the crowns of Austria and Hungary, warned that economic cooperation alone would not satisfy the peoples of Europe and that European unification could not succeed unless it was imbued with an abstract principle. Only something as mystical, he wrote, as the Holy Roman Empire could give people hope, a sense of religious renewal and combat the pernicious effects of local interest, chauvinism, xenophobia and racism.

Today’s European crisis indeed shows that great political institutions cannot be constituted solely on a rational basis or through the bureaucracy and incrementalism of Brussels. The true purpose of the European Union is to bring about peace, prosperity and equality among the diverse regions and groups. Peace has indeed prevailed on most of the Continent, but in the last few years, with prosperity endangered, continued regional inequality has become even more blatant, while radical nationalism has raised its ugly head.

Historic empires provided ideals — whether universal Christian unity or the Marxist-Leninist dogmas of the Soviet Union — in which people were able to believe, no matter how flawed the ruler and how corrupt the imperial institutions. So long as people believe in the principles, the system is likely to endure.

Today’s Europe possesses idealistic institutions like the Erasmus program, which allows student exchange; the European University Institute in Florence; the Jean Monnet program for distinguished scholars; and the Leonardo da Vinci program for vocational education. But these are clearly not enough to overcome regional tensions, bitter north-south divisions and a general indifference to the European project.