三皇五帝
Taoist documents from as early as the Han Dynasty claimed that Lao Tzu appeared on earth as different persons in different times beginning in the legendary era of Three Sovereigns and Five Emperors. The (ca. 3rd century BC) "Chuang Tzu" states: "Birth is not a beginning; death is not an end. There is existence without limitation; there is continuity without a starting-point. Existence without limitation is Space. Continuity without a starting point is Time. There is birth, there is death, there is issuing forth, there is entering in."