To write for the screen or the stage is to accept that your work is not the final work — it is the architecture from which others will build, which requires a different kind of authorship: less visible, more structural, more trusting of the actors, directors, and designers who will complete what you have only begun. The constraint of scene — of visible action and audible speech as the only instruments — is also a clarifying discipline that prevents the writer from hiding behind reflection or summary. What is not enacted cannot be shown; the dramatic writer must make the invisible visible through what characters do.
Each step builds on the last.