There are thousands of material forms in nature. Why did Thales describe water as the source of everything? Thales found through observation that "all seeds are conceived from wetness, everything is nourished by wetness, and water is the source of wetness". According to Thales, water has the nature of movement and change. It is not only the source of everything, but also the cause of all movements and changes. Thales once said that "a magnet has a soul because it attracts iron". He understood the soul as something that "has the ability to cause movement" and advocated that everything has a "soul". However, Thales' understanding of "soul" is not a spiritual thing, but the moisture produced by water, which permeates the universe and constitutes the reason for the movement of all things. There is no distinction between the material cause and motivation of everything here. The idea that the origin of matter is considered to be inert and passive, while the initiative is attributed to an independent spiritual entity was formed in later Greek philosophy.

Thales

When Thales regarded water as the root of all things, he first expressed his thoughts about primitive people in a philosophical way (rather than a mythical way) (although the concept of primitive people was first used by his student anaximander). Therefore, he is regarded as the founder of Greek philosophy.