This term means to educate and teach according to people’s caliber and their interests. Cai (材) refers to factors such as people’s caliber and interests, and their level of education. This is an educational and pedagogical principle first practiced by Confucius (551-479 BC), and later summarized and established by others. We may say that the core concepts of this principle are shuaixing (率性 acting in accordance with human nature) as described in The Book of Rites, and jinxing (尽性 making full use of human nature) as described in The Book of Changes. It has been widely accepted to this day, and its gist is that in education and pedagogy, the choice of subject matter, methods and goals must vary according to the individual characteristics of the audience if they are to achieve better outcomes. This principle has been corroborated through psychology and pedagogy, and has become a fundamental concept in the modern science of education.