La vie est un miroir: si tu y regardes en souriant, il te sourit en retour.
生活是一面镜子，如果你对它微笑，它也会对你微笑。
逻辑学研究不仅仅是关于形式系统，更是关于人类推理的本质。
You have to be thick-skinned in this business.
The merit of Marx is that he suddenly produces a qualitative change in the history of social thought. He interprets history, understands its dynamic, predicts the future, but in addition to predicting it, he expresses a revolutionary concept: the world must not only be interpreted, it must be transformed.