真理是一种发生在观念上的东西。

Youth is not a time of life; it is a state of mind; it is not a matter of rosy cheeks, red lips and supple knees; it is a matter of the will, a quality of the imagination, a vigor of the emotions; it is the freshness of the deep springs of life.

不要害怕改变和成长。

Policy should be based on evidence, not ideology.

解释：冬天不洗冰水，并不是吝惜冰；夏天不烤火，也不是舍不得火。而是因为这样做对身体不适宜。

生活是一场所有人都要参与的闹剧。