Yin and Yang Arrangement
by Fu Hsi – circa 3300 BC
Fu Hsi’s arrangement of Yin trigrams and Yang trigrams is based on the cycle of the seasons or the cycle of the day. The 4 yin trigrams are all trigrams in which darkness is increasing. The four Yang trigrams are all trigrams in which daylight is increasing.
They simply divide the day and the year in half. This reveals the astrological and scientific nature of Fu Hsi’s application of the I Ching.