What does a circle stand for in philosophy?

In my opinion, the cycle has no beginning and no end. The circle is a whole, with no protrusion or defect. A circle means that you stand in its center and have no direction, but if you walk in any direction at will, the result will be the same. A circle is the same as two faces, and it makes no difference whether you come or go. Circle is the foundation of Tai Chi. Circles exist in all substances in the world. . . . The circle represents too much, but the circle is actually nothing, it is just what people call a "circle".