There is a flow in the universe, and it is called dao. Dao flows slowly, however; it is never stagnant and is incredibly powerful and keeps things in the universe balanced and in order. It manifests itself through change of seasons, cycle of life, shifts of power, time, and so forth. Dao has a strong and deep connection with cosmology and the natural world, as the most well-known Daoist philosophers Laozi and Zhuangzi agreed. Dao is the law of Nature. When you follow dao, you become one with it. And it is best to also understand chi, because chi and dao go hand in hand. Chi is a Chinese term that is translated as breath, vapour, and energy. Because chi is the energy that circulates the universe, it can be said that dao is ultimately a flow of chi. Being one with dao brings best outcomes, because that way things fall into place that they are meant to be.
The concept of Tao is based upon the understanding that the only constant in the universe is change, and that we must understand and be in harmony with this change. The change is a constant flow from non-being into being, potential into actual, yin into yang, female into male. The symbol of the Tao, called the Taijitu, is the yin yang confluently flowing into itself in a circle.
The Tao is the main theme discussed in the Tao Te Ching, an ancient Chinese scripture attributed to Lao Tsu. This book does not specifically define what the Tao is; it affirms that in the first sentence, "The Tao that can be told of is not an Unvarying Tao." Instead, it points to some characteristics of what could be understood as being the Tao. Below are some excerpts from the book.
Tao as the origin of things: "Tao begets one; One begets two; Two begets three; Three begets the myriad creatures." Tao as an inexhaustible nothingness: "The Way is like an empty vessel / That yet may be drawn from / Without ever needing to be filled." Tao is omnipotent and infallible: "What Tao plants cannot be plucked, what Tao clasps, cannot slip." In the Yi Jing, a sentence closely relates Tao to Yin-Yang or Taiji, asserting that "one Yin, one Yang, is what is called the Tao". Being thus placed at the conjunction of Yin and Yang alternance, Tao can be understood as the continuity principle that underlies the constant evolution of the world.
The Tao that can be told is not the eternal Tao, The name that can be named is not the eternal name. The nameless is the beginning of heaven and earth. The named is the mother of ten thousand things. Ever desireless, one can see the mystery. Ever desiring, one can see the manifestations. These two spring from the same source but differ in name; this appears as darkness. Darkness within darkness. The gate to all mystery.