But no man can lead a public career really worth leading, no man can act with rugged independence in serious crises, nor strike at great abuses, nor afford to make powerful and unscrupulous foes, if he is himself vulnerable in his private character.
 Theodore Roosevelt, Theodore Roosevelt; an Autobiography (1913). copy citation

Context

“A man can of course hold public office, and many a man does hold public office, and lead a public career of a sort, even if there are other men who possess secrets about him which he cannot afford to have divulged. But no man can lead a public career really worth leading, no man can act with rugged independence in serious crises, nor strike at great abuses, nor afford to make powerful and unscrupulous foes, if he is himself vulnerable in his private character. Nor will clean conduct by itself enable a man to render good service. I have always been fond of Josh Billings's remark that "it is much easier to be a harmless dove than a wise serpent." There are plenty of decent legislators, and plenty of able legislators;” source