统一自然界所有力的挑战是几十年来推动理论物理学发展的动力之一。

写作不仅仅是一种职业；它是一种生活方式，对真理和美的承诺。

The stranger is close to us, insofar as we feel between him and ourselves common features of a national, social, occupational, or generally human, nature. He is far from us, insofar as these common features extend beyond him or us, and connect us only because they connect a great many people.

人心的差异，就像人的面孔一样各不相同。