Let it first be said that these three laws are far from being of equal importance as regards the theory of the ludicrous. INVERSION is the least interesting of the three. It must be easy of application, however, for it is noticeable that, no sooner do professional wits hear a sentence spoken than they experiment to see if a meaning cannot be obtained by reversing it,--by putting, for instance, the subject in place of the object, and the object in place of the subject. It is not unusual for this device to be employed for refuting an idea in more or less humorous terms. One of the characters in a comedy of Labiche shouts out to his neighbour on the floor above, who is in the habit of dirtying his balcony, "What do you mean by emptying your pipe on to my terrace?" The neighbour retorts, "What do you mean by putting your terrace under my pipe?" There is no necessity to dwell upon this kind of wit, instances of which could easily be multiplied. The RECIPROCAL INTERFERENCE of two sets of ideas in the same sentence is an inexhaustible source of amusing varieties. There are many ways of bringing about this interference, I mean of bracketing in the same expression two independent meanings that apparently tally. The least reputable of these ways is the pun. In the pun, the same sentence appears to offer two independent meanings, but it is only an appearance; in reality there are two different sentences made up of different words, but claiming to be one and the same because both have the same sound. We pass from the pun, by imperceptible stages, to the true play upon words. Here there is really one and the same sentence through which two different sets of ideas are expressed, and we are confronted with only one series of words; but advantage is taken of the different meanings a word may have, especially when used figuratively instead of literally. So that in fact there is often only a slight difference between the play upon words on the one hand, and a poetic metaphor or an illuminating comparison on the other. Whereas an illuminating comparison and a striking image always seem to reveal the close harmony that exists between language and nature, regarded as two parallel forms of life, the play upon words makes us think somehow of a negligence on the part of language, which, for the time being, seems to have forgotten its real function and now claims to accommodate things to itself instead of accommodating itself to things. And so the play upon words always betrays a momentary LAPSE OF ATTENTION in language, and it is precisely on that account that it is amusing. INVERSION and RECIPROCAL INTERFERENCE, after all, are only a certain playfulness of the mind which ends at playing upon words. The comic in TRANSPOSITION is much more far-reaching. Indeed, transposition is to ordinary language what repetition is to comedy.