Throughout the ages, it is difficult to write with a pen. What is it? Because it's passed down from time to time.

3. It is not easy to write with a pen, that is, it is not easy to write, which seems incomprehensible, but it also changes with time and people.

Everyone's brush strokes are different. Even the same point, there are many different forms that need different strokes to match the performance, and there are two different strokes: internal and external. Different times and different calligraphers can evolve into ever-changing ones.

In fact, what Zhao Mengfu is talking about here is not the specific brushwork, but the essential brushwork.

6. Good-looking books or ugly books are also characterized by the eternity of ever-changing forms. The pen is good, but it belongs to calligraphy.

7. It is good to leave the eternal and incomprehensible essence as an ever-changing form, but it does not belong to calligraphy.