思想开阔，才能包容天下的千山万壑；思想谦虚，才能接受天下的真知大德；思想平明，才能纵论天下的善恶得失；思想深沉，才能讨论天下的学说哲理；思想稳定，才能应付天下的风云变幻。

Every mathematical problem has a solution; it just takes time and effort to find it.

The end of history will be a very sad time. The struggle for recognition, the willingness to risk one's life for a purely abstract goal, the worldwide ideological struggle that called forth daring, courage, imagination, and idealism, will be replaced by economic calculation, the endless solving of technical problems, environmental concerns, and the satisfaction of sophisticated consumer demands.