By practicality――not a happy term, I confess, and one which I use only because I cannot think of any other single word――I mean the quality of helping the play forward, either by getting on with the evolution of the situations, or by exhibiting the drama which is the result of the situations (I must add, parenthetically, that by situations I do not mean merely external happenings――the term properly includes both characters and events, and their reciprocal action on one another). A play is a very short thing; a very solid four-act play――I am talking of the modern theatre now――will not cover more than 140 to 150 ordinary type-written sheets; a novel of the ordinary length will cover from three to four hundred. The obvious result is that the author has not, to put it colloquially, much time to play about. He may allow himself a little of what is technically termed ‘relief’. A good line pays for its place. But broadly speaking, all the dialogue has to work――each line has its task of advancing action or exhibiting character. Now only so many lines being possible between the rise and the fall of the curtain, it is clear that there is no room for digression or for rambling――things that are often most delightful in a book, where space and time are practically unlimited. More than this. Not only is there no space for rambling and irrelevant talk, but the necessary talk――the talk that is helpful and pertinent――must at the same time carefully consult the limits of space. There are a lot of points to be made in every act――aye, in every scene. The playwright cannot afford too much space to any one point. And the point must not only be made with all possible brevity――it must be made with all possible certainty, so that there may be no need of going back to it, no need of repetition; it should be stuck straight into the audience’s mind, as one sticks a pin into a chart. Hence there is need of directness――a certain quality of unmistakableness――one might almost say bluntness, when one compares theatrical dialogue with some of the minutely wrought novel dialogue to which I have referred to-night. But what then――I’m afraid you will be beginning to ask――what then, if you are right, is to become not only of the literary graces of style, but also of the intellectual quality of your work――of its profundity, of its subtlety, of its delicacy? Well, I can make only one answer――and being to-night, as I say, in the happy pastures of theory――I can give it light-heartedly. You must keep all those, and manage to harmonize them with your brevity and your certainty. That is one of the reasons――not the only one――why it is distinctly difficult to write good plays, not very easy to write even what are often contemptuously referred to as commercially successful plays――and not absolutely easy to write anything that can be called in any serious sense a play at all. There is a great deal of difference between just being a bad play and not being a play at all.