What is the evaluation standard of ancient and modern calligraphers?

Calligraphy theory was not systematic in ancient times ~ there were no specific standards for calligraphers, but their views on calligraphy were actually the standards for calligraphers ~ that is to say, what kind of people can reach the height he thinks is the calligrapher in their hearts. But in modern Shenzhong, calligraphers are divided into good calligraphers and calligraphers, and I think a real calligrapher should not only be good at books ~ ~ but also have profound cultural accomplishment ~ and be proficient in poetry, calligraphy and printing, which is the highest level calligrapher.