… is from page 119 of Thomas Sowell’s superb 1984 book, Civil Rights: Rhetoric or Reality?:
The past may be many things, but it is clearly irrevocable. Its sins can no more be purged than its achievements can be expunged. Those who suffered in centuries past are as much beyond our help as those who sinned are beyond our retribution. To dress up present-day people in the costumes and labels of history and symbolically try to undo the past is to surpass Don Quixote and jeopardize reality in the name of visions.