Just like the tactics of the great generals, by laying out the square in advance with clear, orderly lines, you insulate yourself from the chaos of improvisation. You mark the boundaries now so you don’t have to later, and excellence is achieved simply by filling them in with your sentences. Each paragraph is given a singular purpose and its only duty is fulfillment. Like I said earlier, with this structure you place the reader in the middle of the square, protected by all sides, and methodically move them forward, defending doubts and objections as they arise. And that is a great essay.