四勿：“非礼勿视，非礼勿听，非礼勿言，非礼勿动。”四端：“恻隐之心，仁之端也；羞恶之心，义之端也；辞让之心，礼之端也；是非之心，智之端也。”颜渊的“四勿”，要牢记心里；下工夫闲静存诚，克服外部的干扰以修养心性；孟子的“四端”，要尽力扩充，下工夫格物致知，由近及远，推己及人。

The strongest principle of growth lies in human choice.

What can be said at all can be said clearly; and whereof one cannot speak thereof one must be silent.

The ending of a mystery novel is often unexpected, yet it makes perfect sense.

"I am not a person who can be easily categorized, and I think that is a good thing."

世界的整个问题在于愚蠢的人和狂热分子总是对自己如此确定，而聪明的人则充满疑虑。