Things are always in the process of flowing into their opposites

According to the ancient Chinese philosophy of the I Ching, the doctrine of
changes, things are always in the process of flowing into their opposites. Extreme
idealists can turn into cynics, passionate lovers into cold-hearted haters. Abject
cowards have the sleeping potential to become heroes, and many saints began as great
sinners. This eternally changing feature of reality is described by the Taoist symbol
of Yin and Yang, the two comma shapes flowing into one another, each with the seed
of its opposite deep in its center.