The definition of a good mathematical problem is the mathematics it generates rather than the problem itself.

世上任何卓越的成就都缺不了热情。

Leadership is about making the tough decisions and standing by them.

The opening up of new markets, foreign or domestic, and the organizational development from the craft shop and factory to such concerns as U.S. Steel illustrate the same process of industrial mutation—if I may use that biological term—that incessantly revolutionizes the economic structure from within, incessantly destroying the old one, incessantly creating a new one.