Why are China's paintings and calligraphy brothers?

If two people are brothers, then they must have a lot in common. However, they are two separate people, and they will have their own characteristics. China's calligraphy and painting are such brothers. Calligraphy and painting are brothers, because they are all changed from primitive paintings and hieroglyphics. Later, when creating, they all used the same tools: the brush, Xuan paper, ink and inkstone called "Four Treasures of the Study". There are many similarities in the methods used in the creative process. However, there are many differences between the two brothers. Calligraphy must be created around specific Chinese characters. Without Chinese characters, it can't be called calligraphy. Calligraphy pays attention to brushwork, brushwork, arrangement between words, momentum from beginning to end and artistic conception of text content, which requires the author to work hard on the whole word. And painting? It always revolves around everything concrete. Even those freehand brushwork ink paintings that seem to be painted casually require some similarity with the real face of things, which is called "spirit likeness". The two brothers have many similarities. Painting meticulous painting is very similar to writing regular script, and creating freehand brushwork is like writing cursive script. Because of this, the relationship between brothers is very close. In order to make Chinese painting vivid, the image in the painting must be tangible and magical, and the tangible and magical depends on the painter's skill of using pen and ink. Therefore, painting Chinese painting must learn and understand calligraphy at the same time. Similarly, calligraphers often practice painting Chinese paintings in order not to make their creations rigid and monotonous.