“Ultimately evil is done not so much by evil people, but by good people who do not know themselves and who do not probe deeply.”

Address at the Conference on Cosmic Design, American Association for the Advancement of Science, Washington, D.C. (April 1999)
This comment is modified in a later article derived from these talks:
:Frederick Douglass told in his Narrative how his condition as a slave became worse when his master underwent a religious conversion that allowed him to justify slavery as the punishment of the children of Ham. Mark Twain described his mother as a genuinely good person, whose soft heart pitied even Satan, but who had no doubt about the legitimacy of slavery, because in years of living in antebellum Missouri she had never heard any sermon opposing slavery, but only countless sermons preaching that slavery was God's will. With or without religion, good people can behave well and bad people can do evil; but for good people to do evil — that takes religion.
:* "A Designer Universe?" at PhysLink.com http://www.physlink.com/Education/essay_weinberg.cfm

“A Friedman doctrine‐- The Social Responsibility Of Business Is to Increase Its Profits” (Sept. 1970)

Edicts of Ashoka (c. 257 BC)

Hope and Memory: Reflections on the Twentieth Century (2003)

Source: Hunted

Quotes from interviews, Sydney Morning Herald interview (2003)
Context: You can make fun with Saddam Hussein jokes … but you can't make fun of, say, the concentration camps. I think my target was not so much evil, but benign stupidity people doing stupid things without realising or, instead, thinking they were doing good.

Interview With The Vampire (1976)
Source: Interview with the Vampire

Variant: The world is dangerous, not because of those who do evil, but because of those who look on and do nothing.