? "Line is the beginning of knowledge, and knowledge is line. Mohist debate puts forward three kinds of knowledge, one is self-knowledge; The second is to know; The third is knowledge. Familiarity comes from personal experience, that is, from "doing" Knowledge is acquired from others, or taught by teachers and friends, or conveyed by books, which can be classified into this category. Say that knowledge is inferred knowledge. " This is an educational theory put forward by Tao Xingzhi, a famous educator. When the pony encountered the problem of crossing the river, he only heard others say that the water was deep. Finally, he didn't know whether the white water was deep or shallow. As a teacher, we should not just think from our own perspective like Uncle Niu and Squirrel, but encourage our children to think more and practice more when they encounter problems, and get real knowledge from practice, like Mama Pony. Because practice is the necessary way to acquire cognition, only practice can produce true knowledge. Pony "knows" the depth of the river, but in the end he can't understand the depth of the river. His mother's encouragement "knows" finally made him understand whether the water is deep or shallow.