But to retrace our steps awhile. It seems that the essence of humour is a certain perception of incongruity. Let us take a single instance. There is a story of a drunken man who was observed to feel his way several times all round the railings of a London square, with the intention apparently of finding some way of getting in. At last he sat down, covered his face with his hands, and burst into tears, saying, with deep pathos, "I am shut in!" In a sense it was true: if the rest of the world was his prison, and the garden of the square represented liberty, he was undoubtedly incarcerated. Or, again, take the story of the Scotchman returning from a convivial occasion, who had jumped carefully over the shadows of the lamp-posts, but on coming to the shadow of the church-tower, ruefully took off his boots and stockings, and turned his trousers up, saying, "I'll ha'e to wade." The reason why the stories of drunken persons are often so indescribably humorous, though, no doubt, highly deplorable in a Christian country, is that the victim loses all sense of probability and proportion, and laments unduly over an altogether imaginary difficulty. The appreciation of such situations is in reality the same as the common and barbarous form of humour, of which we have already spoken, which consists in being amused at the disasters which befall others. The stage that is but slightly removed from the lowest stage is the theory of practical jokes, the humour of which is the pleasure of observing the actions of a person in a disagreeable predicament which is not so serious as the victim supposes. And thus we get to the region illustrated by the two stories I have told, where the humour lies in the observation of one in a predicament that appears to be of a tragic character, when the tragic element is purely imaginary. And so we pass into the region of intellectual humour, which may be roughly illustrated by such sayings as that of George Sand that nothing is such a restorative as rhetoric, or the claim advanced by a patriot that Shakespeare was undoubtedly a Scotchman, on the ground that his talents would justify the supposition. The humour of George Sand's epigram depends upon the perception that rhetoric, which ought to be based upon a profound conviction, an overwhelming passion, an intense enthusiasm, is often little more than the abandonment of a personality to a mood of intoxicating ebullience; while the humour of the Shakespeare story lies in a sense of the way in which a national predilection will override all reasonable evidence.