Examine the records of history, recollect what has happened within the circle of your own experience, consider with attention what has been the conduct of almost all the greatly unfortunate, either in private or public life, whom you may have either read of, or hear of, or remember, and you will find that the misfortunes of by far the greater part of them have arisen from their not knowing when they were well, when it was proper for them to set still and to be contented.
Adam Smith, The Theory of Moral Sentiments, p. 252
