"The Story Of Stupidity" by James F. Welles.
His point of departure was Barbara Tuchman's "March Of Folly," where she asked why nations so often pursue idiotic policies that are clearly against their interests. (How the British lost the American colonies, how the Popes provoked the Reformation, the U.S. in Vietnam, etc.)
One of my favorite Welles bits, from Chapter VI, "Stupidity Reformed:"
As theologians, the Protestant reformers replaced the authority of the Catholic Church with the authority of the Bible, which they opened to the public.
The inevitable but unforeseen result was that every individual who could read thought God could communicate directly with him. Unfortunately, as recorded in the Bible, the voice of God often rambles incoherently like that of a slightly schizoid manic-depressive with delusions of grandeur.
Worse yet, his Protestant readers promptly splintered into numerous sects which agreed only on one point—they wanted to be separate. By 1650, there were 180 sects, all based on the Bible and each more dogmatically intolerant than the next...http://www.stupidity.com/story1final/