Mencius has observed， \"That whereby man differs from the lower animals is but scarce（希， xi ）\" Zhu Xi has noted that this remark means there are very few differences between humans and animals，But I think that \"xi\" in this remark perhaps also covers the meaning \"rare and uncommon.\"As a kind of animals， humans naturally have very few differences from other animals， but these tiny differences indeed matter and are therefore valuable.
　　Then， what are our differences from animals or advantages over them?In my opinion， humans are superior to animals not because our teeth or hands are more capable， our bodies are stronger and more sophisticated，not because we run faster， have more brilliant dwellings or eat more exquisite food. We are differentiated from animals mainly because we are morally advanced， which is represented in Mencius' four terms， including sympathy， sense of shame， courtesy and a clear mind to distinguish between right and wrong.
　　\"Xiushen\"（修身，cultivation of one's moral self）， as our ancestors kept stressing， is to maintain and promote such differences， so that we would not abandon the few advantages endowed by Heaven or obtained through evolution and backslide into a barbaric status. Xiushen is the key to self-cultivation through pursuit of knowledge and rectification of mind， and to the regulation of families， states and the world.
　　Xiushen， therefore， is to cultivate an indestructible spirit. Though it sounds illusory， there are innumerable ways of practicing such cultivation.In the long history of China， numerable sages have set up examples for us to cultivate ourselves. Despite the vast diversity of their paths of lifeand achievements， they all show us， through their spiritual struggles， their splendid personalities and the glory of human nature.
　　Today's society is very different from the past， marked by changing environment and faster pace of life. For this reason， we should be more consistently and diligently cultivating ourselves， so that we can stay true and firm to our aspirations.
　　We wish that this series of picturebooks would offer children a glimpse into ancient sages' noble character， self-discipline and social commitment. Perhaps， a worthy life of constant self-improvement could start from these books.