The word "自己" is formed through the compounding of two ancient, synonymous roots for "self", creating a reinforced and abstract concept of selfhood. The character "自" originally depicted a nose, used in early Chinese to reflexively point to oneself (as one points to their own nose), while "己" was one of the ten "Heavenly Stems" used in calendrical systems that was adopted to mean one's own person or private sphere. By combining these two self-referential symbols, the compound strengthens and universalizes the idea into a single, cohesive term meaning "oneself" or "self".