To become a good actor one must learn as long as he lives from the boyhood till the old age. Zeami's logic of 'Nenrai-keiko' may be called the theory of learning grades through life, according to the actor's mind-and-body development. There are seven learning grades: (1) seven years old, (2) from twelve or thirteen, (3) from seventeen or eighteen, (4) twenty-four or twenty-five, (5) thirty-four or thirty-five, (6) forty-four or forty-five, (7) fifty or after that. Each grade has its own educational and psychological problems about the goals, contents and methods of learning. Zeami says that he inherited this theory from his father, Kwannami, who built it up with his rich experiences. We will now be able to read his theory of 'Nenrai-keiko' in "Kwadensho," which is one of Zeami's famous writings kept secret except his successors. And we will find the fact that an actor's consciousness of his ability is gradually deepened through his lifelong learning process.