Yin (negative) and Yang (positive) which fills up as a whole complement each other and is really a description of the cycles of nature. Yin and Yang are a pair of complementary forces that move continuously in this universe.
- the internal etc.
- the external etc.
A common mistake we make is identifying the Yin and yang as two separate forces, which move to their extremes you don’t want to be either only yin or yang. But Yin and Yang are one inseparable force, which continuously evolve with and into each other. The balances of the complementary forces of Yin/Yang interact with each other to achieve harmony.