Lao Tzu (Chinese: 老子; pinyin: Lǎozǐ; Wade-Giles: Laosi; also Laozi, Lao Tse, Lao Tu, Lao-Tsu, Laotze, Laosi, Lao Zi, Laocius, Lao Ce, and other variations) was a mystic philosopher of ancient China, best known as the author of the Tao Te Ching (often simply referred to as Laozi).