Suffering! We owe to it all that is good in us, all that gives value to life; we owe to it pity, we owe to it courage, we owe to it all the virtues.

To study history is to learn the grammar of time.

积聚的水如果不深，就无力浮起大船。倒一杯水在堂前的凹地，芥草浮在上面就是小船了，放一只水杯在上面就动不了了，是因为水浅而船大。聚集的风如果不大，就无力载负巨大的双翼，因而大鹏扶摇而上九万里，疾风在下面劲吹，然后才能凭借风力，背负蓝天而无可阻挡，才能够一路南飞。