one.  For we are acquainted with the natural one—­the one which we should have chosen instinctively.  So it will be enough if the effort of comic invention bears on the other, and on the other alone.  No sooner is the second set before us than we spontaneously supply the first.  Hence the following general rule:  A comic effect is always obtainable by transposing the nature expression of an idea into another key.

The means of transposition are so many and varied, language affords so rich a continuity of themes and the comic is here capable of passing through so great a number of stages, from the most insipid buffoonery up to the loftiest forms of humour and irony, that we shall forego the attempt to make out a complete list.  Having stated the rule, we will simply, here and there, verify its main applications.

In the first place, we may distinguish two keys at the extreme ends of the scale, the solemn and the familiar.  The most obvious effects are obtained by merely transposing the one into the other, which thus provides us with two opposite currents of comic fancy.

Transpose the solemn into the familiar and the result is parody.  The effect of parody, thus defined, extends to instances in which the idea expressed in familiar terms is one that, if only in deference to custom, ought to be pitched in another key.  Take as an example the following description of the dawn, quoted by Jean Paul Richter:  “The sky was beginning to change from black to red, like a lobster being boiled.”  Note that the expression of old-world matters in terms of modern life produces the same effect, by reason of the halo of poetry which surrounds classical antiquity.

It is doubtless the comic in parody that has suggested to some philosophers, and in particular to Alexander Bain, the idea of defining the comic, in general, as a species of degradation.  They describe the laughable as causing something to appear mean that was formerly dignified.  But if our analysis is correct, degradation is only one form of transposition, and transposition itself only one of the means of obtaining laughter.  There is a host of others, and the source of laughter must be sought for much further back.  Moreover, without going so far, we see that while the transposition from solemn to trivial, from better to worse, is comic, the inverse transposition may be even more so.

It is met with as often as the other, and, apparently, we may distinguish two main forms of it, according as it refers to the physical dimensions of an object or to its moral value.