“If you can do no good, at least do no harm.”

Panel with Edward Said at Columbia University, New York, April 1999 http://www.democracynow.org/article.pl?sid=03/04/07/042214
Quotes 1990s, 1995-1999
Context: Let me just put the whole thing in a kind of mundane level. Like, suppose you walk out in the street, this evening, and you see a crime being committed, you know, somebody is robbing someone else. Well, you have three choices. One choice is to try to stop it, maybe you call 911 or something. Another choice is to do nothing. A third choice is to pick up an assault rifle and kill 'em both, and kill a bystander at the same time. Well, suppose you do that, and somebody says, "Well, you know, why did you do that?" And you say, "Look, I couldn't stand by and do nothing." I mean, is that a response? If you can think of nothing that wouldn't do harm, then do nothing. And the same is true, magnified, in international affairs. Apart from the fact that there were things that could have been done.

Epidemics, Book I, Ch. 2, Full text online at Wikisource
Variant translation: The physician must be able to tell the antecedents, know the present, and foretell the future — must mediate these things, and have two special objects in view with regard to disease, namely, to do good or to do no harm.
Paraphrased variants:
Wherever a doctor cannot do good, he must be kept from doing harm.
Viking Book of Aphorisms : A Personal Selection (1988) by W. H. Auden and Louis Kronenberger, p. 213.

Source: You Learn by Living: Eleven Keys for a More Fulfilling Life

Quoted by Louise Creighton in Life and Letters of Mandell Creighton, vol. 2 http://books.google.com/books?id=XFrIeWud0_wC&q=%22no+people+do+so+much+harm+as+those+who+go+about+doing+good%22&pg=PA501#v=onepage. (1905)

The Complete Neurotic's Notebook (1981), Unclassified

Source: Six Characters in Search of an Author

Source: Uncle Tom's Cabin (1852), Ch. 28.

As quoted in American Heritage (December 1955), p. 44
Context: I disagree with my brother Charles and Theodore Roosevelt. I think that Lee should have been hanged. It was all the worse that he was a good man and a fine character and acted conscientiously. These facts have nothing to do with the case and should not have been allowed to interfere with just penalties. It's always the good men who do the most harm in the world.

Source: Uprooted