A moral being is one who is capable of reflecting on his past actions and their motives.

"The major threats to survival that our ancestors faced - predators, starvation, disease - left their mark on our fears and anxieties."

在理论物理学的领域里，每一个发现都会带来新的问题和挑战。

我不想成为一个象征，我想做我自己。