The Pyramid Principle by Barbara Minto (The logic of writing)

The pyramid structure
A person that seeks to learn your thinking about a particular subject faces a complex task. George A. Miller describes in his treatise “The magical number seven, plus or minus two” a pattern governing the process of our mind. Whenever we encounter a number of items the mind begins to group them into logical categories so they can be retained. The mind will automatically impose order on everything around it. This tendency of the mind is nicely illustrated by the Greeks who grouped stars into figures instead of pinpoints of lights. As the listener has to take in your story line by line, he must take each of these, digest them, relate them and hold them together. He will invariably find the job easier if your ideas come to him as a pyramid. When you group together a number of sentences into a paragraph, you do so, because the sentences have a logical relationship. All of your sentences are needed to express a single idea of the paragraph, which is effectively a summary of the paragraph. Stating this summary sentence raises you to the next level of abstraction. On this level of abstraction you again combine a number of paragraphs to form a section. These paragraphs and no others are needed to express the single idea of the section, which again will be the summary of the ideas in the paragraphs below. Exactly the same thinking holds true in bringing together sections to form a document and the single idea of the document will be expressed in the executive summary. If you have made the pyramid structure correctly your major point will be explained and defended by the in ever greater detail. Fortunately we can check if the pyramid grouping is correct by the following rules: • Ideas at any level in the pyramid must always be summaries of the ideas grouped below them • Ideas in each grouping