On why the study of history is important.....

Man is a rational animal - so at least I have been told.  Throughout a long life, I have looked diligently for evidence in favor of this statement, but so far I have not had the good fortune to come across it, though I searched in many countries spread over three continents.  On the contrary, I have seen the world plunging continually further into madness.  I have seen great nations, formerly leaders of civilization, led astray by preachers of bombastic nonsense.  I have seen cruelty, persecution, and superstition increasing by leaps and bounds, until we have almost reached the point where praise of rationality is held to mark a man as an old fogey regrettably surviving from a bygone era.  All this is depressing, but gloom is a useless emotion.  In order to escape from it, I have been driven to study the past with more attention than I had formerly given to it, and have found, as Erasmus found, that folly is perennial and yet the human race has survived.  The follies of our own times are easier to bear when they are seen against the background of past follies.

-Bertrand Russell, from the essay An Outline of Intellectual Rubbish, as published in Unpopular Essays