王陽底「知行合一」說可上溯至孟子底「良知」學說。康德在〈論俗語所謂：這在理論上可能是正確的，但不切實際〉一文中則分別從道德學、國內法、國際法三個層面討論理論與實踐之關係。在道德底層面上，康德得到一項結論：凡是對於理論而言是正確的，對於實踐也必然有效。理論與實踐在道德中的這種一致性正是王陽明「知行合一」說，以澄清有關「知行合一」說的若干誤解。本文指出：儘管王陽明底「知行一」說與「心即理」、「致良知」之說並非 同時提出，但此三說在義理上是互涵的。

　　　　　Wang Yang-ming's doctrine of the "unity of moral knowledge and action" (chih-hsing ho-i) can be traced back to Mencius' theory of liang-chih (良知). Similiarly, Kant has discussed the relationships of theory to practice on three different levels in his article, "On the Common Saying:' This May be True in Theory, but it does not Apply in Practice'". He proposed the unity of theory and practice in moral philosophy. So in the light of Kant�s doctrine of theory and practice. I interpret Wang�s doctrine of the �unity of moral knowledge and action" with a view to clarifying some misinterpretations of it. Thereby, I demonstrate that this doctrine is logically interconnected with Wang�s other two doctrines, namely, the doctrine of hsin-chi-li (心即理) and that of chih liang-chih (致良知), although these tree doctrines were advanced by him different times.