Every civilization has its one basic principle, one single, supreme, determining conception, and every endeavour of men within that civilization is true, unconsciously and irrevocably, to that one principle. Every human soul has a style of its own. Its one basic theme. You'll see it reflected in every thought, in every act, every wish of that person. The one absolute, the one imperative in that living creature. Years of studying won't show it to you. His face will. You'd have to write volumes to describe a person. Think of his face. You need nothing else.
Excerpt for Ayn Rand's the Fountainhead