The moon dims or shines; it waxes or wanes. Nothing is perfect, not even in the olden days. 人之于文学也,犹玉之于琢磨也。 Learning and culture arc to a person what polished and grinding arc to jade. 三人行,必有我师焉。择其善者而从之,其不善者而改之。 Among any three people walking....