“Those who understand evil pardon it.”
#167
1900s, Maxims for Revolutionists (1903)
Help us to complete the source, original and additional information
George Bernard Shaw 413
Irish playwright 1856–1950Related quotes

Dennis Prager, Speaking at the 20th Anniversary Gala of the Freedom Center https://www.youtube.com/watch?v=4pCAhVStBIY (2 February 2008), retrieved 26 August 2015
2000s

“Those who corrupt the public mind are just as evil as those who steal from the public purse.”
Speeches of Adlai Ewing Stevenson (1952), p. 99

“The world is divided into those who understand me and those who don’t.”
In the case of the latter, I simply leave them to torment themselves trying to gain my sympathy.
Aleph (2011)

St. 25.
The Devil's Walk http://www.rc.umd.edu/editions/shelley/devil/devil.rs1860.html (1799)

“Those who know, do. Those that understand, teach.”
This and many similar quotes with the same general meaning are misattributed to Aristotle as a result of Twitter attribution decay. The original source of the quote remains anonymous. The oldest reference resides in the works of George Bernard Shaw, Man and Superman (1903): "Maxims for Revolutionists", where he claims that “He who can, does. He who cannot, teaches.”. However, the related quote, "Those who can, do. Those who understand, teach" likely originates from Lee Shulman in his explanation of Aristotlean views on professional mastery: Source: Shulman, L. S. (1986). Those who understand: Knowledge growth in teaching. Educational Researcher, 15(2), 4 - 14. Stable URL: http://www.jstor.org/stable/1175860
Misattributed
Variant: Those who can, do, those who cannot, teach.

“Those who truly understand their faiths understand the stories are metaphorical.”
Source: The Da Vinci Code

Source: The Tales of Alvin Maker, Alvin Journeyman (1995), Chapter 10.

Part III : Selection on Education from Kant's other Writings, Ch. I Pedagogical Fragments, # 52
The Educational Theory of Immanuel Kant (1904)