Chesterton on children's love of justice

Sometime ago I went with some children to see Maeterlinck's fine and delicate fairy play about the Blue Bird that brought everybody happiness. For some reason or other it did not being me happiness, and even the children were not quite happy. I will not go so far as to say that the Blue Bird was a Blue Devil, but it left us in something seriously like the blues. The children were party dissatisfied with it because it did not end with a Day of Judgment; because it was never revealed to the hero and heroine that the dog had been faithful and the cat faithless. For children are innocent and love justice; while most of us are wicked and naturally prefer mercy.