All this lengthy consideration of selection makes for unity of action in the story resulting. Some unity of action, whether the story be slight or complicated, there must be. Of the three great unities over which there has been endless discussion, Action, Place, and Time, the modern dramatists, as we shall see, treat Place with the greatest freedom, and are constantly inventing devices to avoid the Time difficulty. With the dramatists of the present, as with the dramatists of the past, however, what they write must be a whole, a unit. Some central idea, plan, purpose, whatever we choose to call it, must give the play organic structure. Story is the first step to this. Which gives most pleasure,--a string of disconnected anecdotes and jests; or a series of them given some unity because they concern some man of note, for instance, Abraham Lincoln; or the same series edited till, taken all together, they make Abraham Lincoln, in one or more of his characteristics, clearer than ever before? Does not a large part of our pleasure in biography come from the way in which it co-ordinates and interprets episodes and incidents hitherto not properly inter-related in our minds? Unity of action is, then, of first importance in story.
There is, however, another kind of unity which has not been enough considered,--what may, perhaps, be called artistic unity. Why is it that a play which begins seriously and for most of its course so develops, only to end farcically, or which begins lightly only to become tragic, leaves us dissatisfied? Because the audience finds it difficult to readjust its mood as swiftly as does the author. _The Climbers_[33] and _The Girl With the Green Eyes_[34] of Clyde Fitch are examples in point. The first begins with such dignity and mysteriousness that its lighter moods, after Act I, seem almost trivial. In the second play the very tragic scene of the attempted suicide, after the light comedy touch of the preceding parts, is distinctly jarring. A recent play which for two acts or more seemingly had been dealing with but slightly disguised figures of the political world had a late scene in which one of these politicians, like Manson in _The Servant in the House_,[35] or The Stranger in _The Passing of the Third Floor Back_,[36] shadowed the figure of Christ himself. The effect was jarring, unpleasant, and confusing, mainly because of its suddenness. It will be noted that in both the plays mentioned, Manson and The Stranger carry their suggestion from the start. Should we know how to take Percinet and Sylvette in _The Romancers_[37] of Rostand did not that opening scene, when these two, in love with being in love, read _Romeo and Juliet_ together, prepare us for all the later fantasy? A dramatist will do well, then, to know clearly before he begins to write whether he wishes his story to be melodrama, tragedy, farce, or comedy of character or intrigue. Unless he does and in consequence selects his illustrative material so that he may give it artistic unity, he is likely to produce a play of so mixed a genre as to be confusing.