The wise and virtuous man is at all times willing that his own private interest should be sacrificed to the public interest of his own particular order or society.
明智而有德行的人在任何时候都愿意为了自己特定阶层或社会的公共利益而牺牲自己的私人利益。
——1963年6月25日在西德市政厅柏林墙前的演说
Mathematics is not a careful march down a well-cleared highway, but a journey into a strange wilderness, where the explorers often get lost.