 Later Taoists interpreted this sequence to mean the Tao ("Dao", "Way"), formless ("Wuji", "Without Ultimate"), unitary ("Taiji", "Great Ultimate"), and binary ("yin" and "yang" or Heaven and Earth).Girardot reasons that "Tao Te Ching" evokes the Tao as "a cosmic principle of the beginnings would seem to make little sense without seeing the possibility that it was rooted in the symbolic remembrance of archaic mythological, especially cosmogonic, themes.