"if you think tough men are dangerous, wait until you see what weak men are capable of.

不要看时钟，做它该做的事。继续前进。

I have come to believe that a great teacher is a great artist and that there are as few as there are any other great artists. Teaching might even be the greatest of the arts since the medium is the human mind and spirit.

The essence of mathematics lies in its freedom.

The past is never dead. It's not even past.

太阳，温柔与生命的源泉，向狂喜的大地倾注炽热的爱。

The number one benefit of information technology is that it empowers people to do what they want to do. It lets people be creative. It lets people be productive. It lets people learn things they didn't think they could learn before, and so in a sense it is all about potential.