“Don’t raise your voice, improve your argument”

“You raise your voice when you should enforce your argument” is an admonishment that has been credited to lexicographer Samuel Johnson (1709-1784). Desmond Tutu, a South African social rights activist and Anglican bishop, often said that his father told him, “don’t raise your voice, improve your argument.” Tutu probably first said this before 1988.
 
A popular undated quotation from Desmond Tutu is:
 
“My father used to say ‘Don’t raise your voice. Improve your argument.’ Good sense does not always lie with the loudest shouters, nor can we say that a large unruly crowd is the best arbiter of what is right.”
 
   
Wikipedia: Desmond Tutu
Desmond Mpilo Tutu (born 7 October 1931) is a South African social rights activist and retired Anglican bishop who rose to worldwide fame during the 1980s as an opponent of apartheid.
 
He was the first black Archbishop of Cape Town and bishop of the Church of the Province of Southern Africa (now the Anglican Church of Southern Africa).
 
Tutu’s admirers see him as a man who since the demise of apartheid has been active in the defence of human rights and uses his high profile to campaign for the oppressed. He has campaigned to fight HIV/AIDS, tuberculosis, poverty, racism, sexism, the imprisonment of Chelsea Manning, homophobia and transphobia. He received the Nobel Peace Prize in 1984; the Albert Schweitzer Prize for Humanitarianism in 1986; the Pacem in Terris Award in 1987; the Sydney Peace Prize in 1999; the Gandhi Peace Prize in 2007;[1] and the Presidential Medal of Freedom in 2009. He has also compiled several books of his speeches and sayings.
 
Google Books 
March 1867, New York Medical Journal, pg. 463:
He should have recollected Dr. Johnson’s reproof to a vituperative antagonist:  “You raise your voice when you should enforce your argument.”
     
Google Books
Leadership (South Africa)
Volume 7
1988
Pg. 60:
Telling boycott-crazed UWC students who disrupt their own lectures “My father used to say: don’t raise your voice, improve your argument”, as Archbishop Tutu did, is one thing.
 
19 December 1988, The Times-Picayune (New Orleans, LA), “Second Cup” by Frank Schneider, pg. E-3, col. 1:
“Until he died, he spoke with a booming voice, a commanding voice. My mother once told him, ‘Conrad, when you want to improve your argument, you raise your voice.”
 
Google Books
A Democratic Vision for South Africa:
Political Realism and Christian Responsibility
By Klaus Nürnberger
Pietermaritzburg: Encounter Publications
1991
Pg. 556:
My father (of Desmond M. Tutu—ed.) used to say, “Improve your argument - don’t raise your voice!” Only those who know their position is untenable and unpersuasive use violence to get their way and on that way lies totalitarianism and despotic rule.
 
Google Books
Tolerance Between Intolerance and the Intolerable
Edited by Paul Ricoeur
Providence, RI: Berghahn Books
1996
Pg. 205:
I (Desmond Tutu—ed.) have often used a saying my father was very fond of, “Don’t raise your voice—improve your argument.”
 
Google Books
The Words of Desmond Tutu: Second Edition
By Desmond Tutu
New York, NY: Newmarket Press
2006
Pg. 52:
“My father used to say ‘Don’t raise your voice. Improve your argument.’ Good sense does not always lie with the loudest shouters, nor can we say that a large unruly crowd is the best arbiter of what is right.”
   
Desmond Tutu Peace Foundation
10 Pieces of Wisdom from Desmond Tutu on his Birthday
Posted on October 7, 2013 by Irwin Kula
(...)
7. “Don’t raise your voice. Improve your argument. Good sense does not always lie with the loudest shouters, nor can we say that a large, unruly crowd is always the best arbiter of what is right.”
   
Google Books
Bartlett’s Familiar Quotations
By John Bartlett
Edited by Geoffrey O’Brien
New York, NY: Little, Brown and Company
2014
Pg. 1959:
Desmond Tutu
1931-
Don’t raise your voice; improve your argument.
Address at the Second Nelson Mandela Annual Lecture, Johannesburg, South Africa [November 23, 2004]