The I Ching or Book of Changes developed out of Taoism, the Chinese philosophy, three to four thousand years before Christ.
The universe in which we live is portrayed by 64 hexagrams, stacks of six horizontal lines. The lines can be either complete - yang - or divided - yin.
Yang has traditionally marked the masculine, creative, and time progression.
Yin has traditionally marked the feminine, receptive, and space or place.
The interaction of these lines within a hexagram creates the situation which we face at a given moment.