Tian (天) is one of the oldest Chinese terms for heaven and a key concept in Chinese mythology, philosophy, and cosmology. During the Shang dynasty (17th―11th century BCE), the Chinese referred to their highest god as Shangdi or Di (帝, 'Lord'). During the following Zhou dynasty, Tian became synonymous with this figure. Before the 20th century, worship of Tian was an orthodox cosmic principle of China.
In Taoism and Confucianism, Tian (the celestial aspect of the cosmos, often translated as "Heaven") is mentioned in relationship to its complementary aspect of Dì (地, often translated as "Earth"). They are thought to maintain the two poles of the Three Realms of reality, with the middle realm occupied by Humanity (人, rén), and the lower world occupied by demons (魔, mó) and "ghosts", the damned, (鬼, guǐ). Tian was variously thought of as a "supreme power reigning over lesser gods and human beings" that brought "order and calm... or catastrophe and punishment", a deity, destiny, an impersonal force that controls events, a holy world or afterlife containing other worlds or afterlives, or one or more of these.
