Choosing a Subject and Theme
Whenever you have a problem, whether you are writing an article or building a doghouse, do not look inside for the solution. Do not ask: “How do I do it? Why don’t I know it?” Look outside and ask: “What is the nature of the thing I want to do?”
What is the nature of an article? First observe that you cannot do everything at once. Whatever you are writing – a theoretical work on a revolutionary idea or a small piece about a narrow concrete – you cannot say everything you know about the subject. You must accept this premise fully, so that it becomes part of your subconscious and operates automatically. You can do this by asking yourself whether you always knew everything you know today. Obviously you did not. Knowledge is acquired in steps.
– Ayn Rand, The Art of Nonfiction