A writer's life is a highly vulnerable, almost naked activity. We don't have to weep about that. The writer makes his choice and is stuck with it. But it is true to say that you are open to all the winds, some of them icy indeed. You are out on your own, out on a limb. You find no shelter, no protection — unless you lie — in which case of course you have constructed your own protection and, it could be argued, become a politician.

主要的义务规则是那些要求或禁止某些行为的规则。

The joy of mathematics lies in the journey of discovery, not just the destination.

创新不仅仅是技术的问题；它关乎改变思维方式并接受新的思考方式。

Mental activity is always directed toward some end.

代数是人类创造的一种智力工具，用于清晰地表达世界的数量关系。