I believe firmly in the value of all vulgar notions, especially of vulgar jokes. When once you have got hold of a vulgar joke, you may be certain that you have got hold of a subtle and spiritual idea. The men who made the joke saw something deep which they could not express except by something silly and emphatic. They saw something delicate which they could only express by something indelicate.... And in the first case it is surely obvious that it is not merely at the fact of something being hurt that we laugh (as I trust we do) when a Prime Minister sits down on his hat. If that were so we should laugh whenever we saw a funeral. We do not laugh at the mere fact of something falling down; there is nothing humorous about leaves falling or the sun going down. When our house falls down we do not laugh. All the birds of the air might drop around us in a perpetual shower like a hailstorm without arousing a smile. If you really ask yourself why we laugh at a man sitting down suddenly in the street you will discover that the reason is not only recondite, but ultimately religious. All the jokes about men sitting down on their hats are really theological jokes; they are concerned with the Dual Nature of Man. They refer to the primary paradox that man is superior to all the things around him and yet is at their mercy.
[G. K. Chesterton, "Cockneys and Their Jokes", in All Things Considered.]
