Edith Wharton,
The Valley of Decision — Book IV, Chapter 9
(1901)
“ If we betray the cause from any merely personal motive we shall have fallen below our earlier selves." He waited again, but she was still silent. "Can you swear to me," he went on, "that no such motive influences you now? That you honestly believe we have been deceived and mistaken? That our years of faith and labour have been wasted, and that, if mankind is to be helped, it is to be in other ways and by other efforts than ours?" ”
