“Avoidable human misery is more often caused not so much by stupidity as by ignorance, particularly our ignorance about ourselves.”

Source: Antony and Cleopatra

“The Socialist Economics of Italian Fascism,” Library of Economics and Liberty, July 6, 2015 http://www.econlib.org/library/Columns/y2015/Samuelsfascism.html

Source: 1960s, Strength to Love (1963), Ch. 4 : Love in action, Sct. 3

Source: Lovingkindness: The Revolutionary Art of Happiness

Cited in Tim Flannery, Atmosphere of Hope. Solutions to the Climate Crisis, Penguin Books, 2015, page 81 ISBN 9780141981048.
Other

Grip interview (1997)
Context: The most important of my achievements, if you want to call them that, was that I successfully introduced mystical ideas into pop culture, which was my obsession and my compulsion when I was 16 years old. So, behind all of this fame and fortune, there was a seeker, on a spiritual path — a young man who wanted to discover and share with others an alternative way of looking at the world. I wanted to save our culture from the stupidity and the bigotry and the ignorance that threatened it. And there was the Buddhist way, and the Celtic way.

2000s, The End of Faith (2004)