
G.W.E. Russell, Collections and Recollections, ch. XIV, Harper & brothers, 1898, p. 136 https://archive.org/details/collectionsandr02russgoog/page/n152. Russell states that was said to him by Arnold himself.
Attributed
Source: Natural History (2003), Chapter 2 “Isol and Corvax” (p. 29)
G.W.E. Russell, Collections and Recollections, ch. XIV, Harper & brothers, 1898, p. 136 https://archive.org/details/collectionsandr02russgoog/page/n152. Russell states that was said to him by Arnold himself.
Attributed
On how social and political crises are seeping into American poetry in “JERICHO BROWN in conversation with MICHAEL DUMANIS” http://www.benningtonreview.org/jericho-brown-interview in Bennington Review (2018 Oct 27)
Source: The Tales of Alvin Maker, Heartfire (1998), Chapter 3.
This Week with Christiane Amanpour http://www.mediaite.com/tv/paul-krugman-newt-gingrich-is-a-stupid-mans-idea-of-what-a-smart-person-sounds-like/, November 20, 2011
The Aliens, p. 113 (originally published in Thrilling Wonder Stories, April 1947).
Short fiction, The Skit-Tree Planet (1947)
Often attributed to Plato, it cannot be found in any of his writings ( see this http://languagelog.ldc.upenn.edu/nll/?p=796). The quote is attributed to Plato in A Dictionary of Thoughts: Being a Cyclopedia of Laconic Quotations from the Best Authors of the World, Both Ancient and Modern (page 560) by Tryon Edwards.
Misattributed
Sam Harris, "Killing the Buddha" http://www.shambhalasun.com/index.php?option=content&task=view&id=2903&Itemid=247 (March 2006)
2000s