Humour, which ought to give rise to only the most light-hearted and gay feelings, can often stir up vehemence and animosity. Evidently it is dearer to us than we realize. Men will take almost any kind of criticism except the observation that they have no sense of humour. A man will admit to being a coward or a liar or a thief or a poor mechanic or a bad swimmer, but tell him he has a dreadful sense of humour and you might as well have slandered his mother. Even if he is civilized enough to pretend to make light of your statement, he will still secretly believe that he has not only a good sense of humour but are superior to most. He has, in other words, a completely blind spot on the subject. This is all the more surprising when you consider that not one man in ten million can give you any kind of intelligent answer as to what humour is or why he laughs.One day when I was about twelve years old, it occurred to me to wonder about the phenomenon of laughter. At first I thought it is easy enough to see what I laugh at and why I am amused, but why at such times do I open my mouth and exhale in jerking gasps and wrinkle up my eyes and throw back my head and halloo like an animal Why do not I instead rap four times on the top of my head or whistle or whirl aboutThat was over twenty years ago and I am still wondering, except that I now no longer even take my first assumption for granted, I no longer clearly understand why I laugh at what amuses me nor why things are amusing. I have illustrious company in my confusion, of course. Many of the great minds of history have brought their power of concentration to bear on the mystery of humour, and, to date, their conclusions are so contradictory and ephemeral that they cannot possibly be classified as scientific.Many definitions of the comic are incomplete and many are simply rewording of things we already know. Aristotle, for example, defined the ridiculous as that which is incongruous but represents neither danger nor pain. But that seems to me to be a most inadequate sort of observation, for of at this minute I insert here the word rutabagas, I have introduced something in congruous, something not funny. Of course, it must be admitted that Aristotle did not claim that every painless in congruity is ridiculous but as soon as we have gone as far as this admission, we begin to see that we have come to grips with a ghost when we think have it pinned, it suddenly appears behind us, mocking us.An all-embracing definition of humour has been attempted by many philosophers, but no definition, no formula had ever been devised that is entirely satisfactory. Aristotle’s definition has come to be known loosely as the "disappointment" theory, or the "frustrated expectation", but he also, discussed another theory borrowed in part from Plato which states that the pleasure we derive in laughing is an enjoyment of the misfortune of others, due to a momentary feeling of superiority or gratified vanity in appreciation of the fact that we ourselves are not in the observed predicament. The paragraph following will most likely discuss ().

A. the writer’s intelligent definition of humour
B. more theories about the mystery of laughter
C. why there is humour
D. the mystery of humour