The fundamental postulate is the "great primal beginning" of all that exists, "t'ai chi" – in its original meaning, the "ridgepole". Later Indian philosophers devoted much thought to this idea of a primal beginning. A still earlier beginning, "wu chi", was represented by the symbol of a circle. Under this conception, "t'ai chi" was represented by the circle divided into the light and the dark, yang and yin, . This symbol has also played a significant part in India and Europe. However, speculations of a Gnostic-dualistic character are foreign to the original thought of the "I Ching"; what it posits is simply the ridgepole, the line. With this line, which in itself represents oneness, duality comes into the world, for the line at the same time posits an above and a below, a right and left, front and back – in a word, the world of the opposites. (1967:lv)