  However, he still insisted that they are different things because they originate from the different sources. According to him, the Four are related to original human nature because they are, as informed by the heavenly principle, inborn and innately good, while the Seven are related to the physical endowment because they arise from contacts with external objects and can be good or evil. The Seven are not genuine moral feelings. From a Mencian perspective, self-cultivation requires the nourishment of the Four and the exercise of emotional control over the Seven. So, for T’oeyge, the Four together with Principle always maintain its transcendent, independent status regardless of the concrete course of events and also preserves its causal efficacy in initiating the desirable patterns of behavior. As he variously puts it in his works such as “the Four-Seven Letters” as well as “Critique on the Position that the Heart/Mind does not have Essence and Function”, “Principle issues (理發)”, “Principle moves (理動)” and “Principle comes into being of itself (理自到)” (Yi Hwang [T’oegye] CW, Vol. 1, Book 16, 464-465a).