朱子對「至善」有非常詳盡的闡述，他認爲「至善」是「事理當然之極」，是「天理、人心之極致」，是「盡夫天理之極而無一毫人欲之私」，是「極好」、「十分好」。儘管「至善」從本體上來講是源於天命、天道、天理，但朱子論「至善」强調的是具體實踐和修身工夫，是「至善」的具體展現和落實，體現在事事物物上。「明明德」、「新民」都要指向「至善」，三者的有機統一才是圓滿和真正的至善。「止於至善」雖然難以完全實現，但作爲修身的總目標、大方向和指南針，又是必須强調的。朱子門人及後學在「至善」問題上有進一步推展，把「至善」與「天命」、「中和」、「皇極」等經典概念範疇作了關聯性討論，豐富了「至善」的內涵。

Zhu Xi put forward many explanations for the concept of ＂the supreme good＂. He believed that ＂the supreme good＂ was ＂in accordance with the truth, it is necessary to do so＂ and ＂it is the extreme of nature, no human desire ＂.It is ＂excellent＂ and ＂very good＂. From the ontological point of view, ＂the supreme good＂ comes from the destiny, the heaven and the heavenly principles, however, Zhu Xi's discussion of ＂the supreme good＂ emphasizes the specific practice and moral cultivation of the method, which is the implementation of the ＂supreme good＂ on specific things.＂Ming Ming De＂(to illustrating illustrious value), ＂Xin Min＂(to renovate the people) all point to ＂the supreme good＂, but the organic unity between them can achieve the true ＂the supreme good＂. Although it is difficult to achieve the goal of ＂reaching the supreme good＂, it must be emphasized that it should be the highest goal of moral cultivation. Zhu Xi's disciples and later scholars had made further progress in explaining the concept of ＂the supreme good＂. They linked the ＂supreme good＂ with the concept of ＂destiny＂, ＂neutralization＂ and ＂Huangji＂ to study these concepts together, which enriched the connotation of ＂the supreme good＂.