I have already carried out my duty. I have proved the Poincaré conjecture and I have nothing more to do in mathematics.
The writer’s duty is to tell the truth, even when it is uncomfortable.
没有道德或不道德的书,只有写得好或写得差的书。
An individual has not started living until he can rise above the narrow confines of his individualistic concerns to the broader concerns of all humanity.