What is the Theory of the five elements?

It is a theory in which everything in nature is considered to be formed by the 5 elements of "tree, fire, soil, metal, and water". They do not exist independently, but in balance with one another.

"Sosho" harmony and "Sokoku" discord

The 5 major elements are related to one another by either "Sosho", which nurtures and promotes the development of the counterpart, and "Sokoku", which restrains and hinders the development of the other. The 5 organs of humans apply to this. We can be healthy when Yin-Yang and the 5 elements are well balanced.

"Sosho" harmony

Tree generates fire - tree burns to make fire.
Fire generates soil - fire produces ash.
Soil generates metal - mountain generates mineral.
Metal generates water - metal forms water (waterdrop) on the surface.
Water generates tree - tree germinates and grows with water.

"Sokoku" discord

Tree cut through soil - tree penetrates into soil.
Fire beats metal - fire melts metal.
Soil conquers water - soil absorbs water or makes water muddy.
Metal defeats tree - metal edge cuts tree.
Water overpowers fire - water extinguishes fire.