The hardest single part of building a software system is deciding precisely what to build.

The first man who， having enclosed a piece of ground， bethought himself of saying 'This is mine，' and found people simple enough to believe him， was the real founder of civil society.

Can a man still be brave if he’s afraid. That is the only time a man can be brave.

朗兰兹纲领是对探索数学未知领域的邀请。