Conservative student group Turning Point USA caused a stir last week by posting pages online from a textbook used at the University of South Carolina. The book calls Ronald Reagan “sexist” and says conservatives “take a basically pessimistic view of human nature” — one in which “people are conceived of as being corrupt.” Several avowed conservatives balked not just at the negative portrayal of Reagan but also at the idea that the conservative persuasion contains a measure of pessimism. On this point, the textbook is right and they are wrong. Russell Kirk was the man credited by William F. Buckley...