This brings us, however, to an important fact, which must by no means be overlooked.  There is a large class of plays—­or rather, there are several classes of plays, some of them not at all to be despised—­the charm of which resides, not in probability, but in ingenious and delightful improbability.  I am, of course, not thinking of sheer fantasies, like A Midsummer Night’s Dream, or Peter Pan, or The Blue Bird.  They may, indeed, possess plausibility of the third order, but plausibility of the second order has no application to them.  Its writs do not run on their extramundane plane.  The plays which appeal to us in virtue of their pleasant departures from probability are romances, farces, a certain order of light comedies and semi-comic melodramas—­in short, the thousand and one plays in which the author, without altogether despising and abjuring truth, makes it on principle subsidiary to delightfulness.  Plays of the Prisoner of Zenda type would come under this head:  so would Sir Arthur Pinero’s farces, The Magistrate, The Schoolmistress, Dandy Dick; so would Mr. Carton’s light comedies, Lord and Lady Algy, Wheels within Wheels, Lady Huntworth’s Experiment; so would most of Mr. Barrie’s comedies; so would Mr. Arnold Bennett’s play, The Honeymoon.  In a previous chapter I have sketched the opening act of Mr. Carton’s Wheels within Wheels, which is a typical example of this style of work.  Its charm lies in a subtle, all-pervading improbability, an infusion of fantasy so delicate that, while at no point can one say, “This is impossible,” the total effect is far more entertaining than that of any probable sequence of events in real life.  The whole atmosphere of such a play should be impregnated with humour, without reaching that gross supersaturation which we find in the lower order of farce-plays of the type of Charlie’s Aunt or Niobe.

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Plausibility of development, as distinct from plausibility of theme or of character, depends very largely on the judicious handling of chance, and the exclusion, or very sparing employment, of coincidence.  This is a matter of importance, into which we shall find it worth while to look somewhat closely.

It is not always clearly recognized that chance and coincidence are by no means the same thing.  Coincidence is a special and complex form of chance, which ought by no means to be confounded with the everyday variety.  We need not here analyse chance, or discuss the philosophic value of the term.  It is enough that we all know what we mean by it in common parlance.  It may be well, however, to look into the etymology of the two words we are considering.  They both come ultimately, from the Latin “cadere,” to fall.  Chance is a falling-out, like that of a die from the dice-box; and coincidence signifies one falling-out on the top of another, the concurrent happening of