Man's survival, from the time of Adam and Eve until the invention of agriculture, must have been precarious because of his inability to ensure his food supply.

Quality is never an accident; it's always the result of intelligent effort.

无产阶级是普遍的阶级，他们的根本锁链是可以破裂的阶级。

快乐不是一件自我存在的东西，它仅是与其他不快乐事情的一个相对比照，这就是快乐的整个情况。