History, with its integrity as a record of the past intact, is a gold mine of experience from many times and peoples under a wider range of circumstances than any given generation can find in its own time. Contemporary plans, theories, beliefs, and hopes can be checked against the record of what has happened in the past when similar notions were put into practice. Merely to discover how often the same ideas have occurred to others, centuries ago, can be a sobering experience for those inclined to become carried away by supposedly new and brilliant insights about an unprecedented situation. But history cannot be a reality check for visions when history is itself shaped by visions. — Thomas Sowell (Black Rednecks and White Liberals^•)