Take the writing on paintings. Apart from it being the artist's own testament, it is also a communication with the people of his own time. Later people can understand how the people of that time lived and felt. No matter whether it be material or spiritual life, both can be perceived in this way.
像是畫上的題字，除了是畫家自己的一種寄託，也是他和時人的溝通，後人可藉以瞭解當時的人如何生活、如何安頓自己的心，不論是物質生活或精神生活都可由此洞見。