What does laughter mean? What common ground can we find between the grimace of a merry-andrew, a play upon words, an equivocal situation in a burlesque and a scene of high comedy? What method of distillation will yield us invariably the same essence from which so many different products borrow either their obtrusive odour or their delicate perfume? The greatest of thinkers, from Aristotle downwards, have tackled this little problem, which has a knack of baffling every effort, of slipping away and escaping only to bob up again, a pert challenge flung at philosophic speculation. Our excuse for attacking the problem in our turn must lie in the fact that we shall not aim at imprisoning the comic spirit within a definition. We regard it, above all, as a living thing. However trivial it may be, we shall treat it with the respect due to life. We shall confine ourselves to watching it grow and expand.