Here is a characteristic piece of comedy from the Book of Scottish Anecdote (seventh edition, 1888). A gentleman upbraids his servant: is it true, he asks him, that you have had the audacity to spread around the idea that your master is stingy? No, no, replies the servant, you won’t find me doing that kind of thing: ‘I aye keep my thoughts to mysel’.’

Comic contradiction tends to reproduce itself at several levels of possibility at once, and that is the case here. First, the servant, thinking that he is absolving himself of the crime of talking disrespectfully about his master, fails to realise that he is simultaneously convicting himself of the crime of thinking disrespectfully about his master. And second, by replying thus to his master, he is not keeping his thoughts to himself but unwittingly sharing them.

Misunderstandings between people are funny because they suggest the great vanity of the self. In that Scottish anecdote, two sealed egoisms talk past each other: the master, thinking of himself, asks the servant if he has been tarnishing his reputation; the servant, also thinking of himself, replies with information about his own mental processes. If this is part of the reason the anecdote raises a smile, comedy would seem to be functioning here at its moral, corrective level, scuffing the shine on vanity and entrapping the diabolical self. This is the rather severe, Bergsonian idea of comedy as cleanser.

But comedy forgives, too. If the spectacle of the vanity of the self makes us laugh, it makes us cry by the same token, because we are saddened by the great illusions of freedom that the self hoards. The Scottish anecdote is too small to generate pathos, but it holds in potential the comic-pathetic idea of a man condemning himself while he thinks he is freeing himself. Don Quixote may be the grandest treatment of the comic illusion of freedom; Part One of Cervantes’s novel ends with Quixote beautifully defending the mission of knight-errancy: ‘I can say that ever since I became a knight-errant I have been courageous, polite, generous, well-bred, magnanimous, courteous, gentle, patient and long-suffering.’ This is not a wholly outrageous self-characterisation. The pain of the passage is that in order to have been some of these things (and he has hardly been gentle), Don Quixote has not been himself: he has been mad. Imagining himself free, he is literally and figuratively imprisoned: as he declaims his virtues, he is being taken, for his own protection, in a caged cart back to his village by a kindly priest and barber.