Have the theme well worked out in your mind before you begin to write. Test your proposed characters by the theme, to see if they conform to the underlying idea of your plot. Test your situations, your sequences, test your whole story from the standpoint of faithful adherence to theme. And I venture to predict that if you will keep to the theme you will have a more closely knit story and smoother action when you finish than you will if you permit your characters and your action to wander about, with little or no regard for the thematic backbone of your story.
Characterization is perhaps the most important phase of working the theme into the plot. Your characters must typify either the idea of the theme, or its very antithesis. For example, allow me to cite again the excellent one given by Mr. Palmer and Mr. Eric Howard in their Photoplay Plot Encyclopedia. In Jack London's "The Sea Wolf" he sought to use the conflict between materialism and idealism as the theme of his story. Wolf Larsen was the very essence of materialism, while in Van Weyden we found the highest type of idealist. There a theme was presented with two characters who gave contrast and conflict. It was a comparatively simple matter, after the author had firmly established these characters in his mind, to work out their struggle in a way that constantly kept the theme of the story in the forefront of action.
There is a chapter in your Handbook devoted to a discussion of some rules and some "don'ts" for photoplaywrights compiled by Mr. William C. De Mille. The importance which he attached to theme is significant for a number of his rules have a direct bearing upon the proper selection and development of theme.
His first rule in the requirements of a successful photoplay reads: "Fundamental idea of interest to the average spectator or patron." That is clear. Mr. De Mille tells you there that you must have a fundamental idea, and he states further that it must be one that will interest the great mass of cinema patrons.
