“If a man is right, he cannot be too radical; if wrong, he cannot be too conservative” has been credited to American humorist Josh Billings, the pen name Henry Wheeler Shaw (1818-1885). “I argue this way, if a man is right, he kan’t be too radical, if he is wrong, he kan’t be conservative” was credited to the “Sayings of Josh Billings” in November 1864.
 
   
Wikiquote: Josh Billings
Josh Billings was the pen name of 19th century American humorist Henry Wheeler Shaw (21 April 1818 – 14 October 1885). He was perhaps the second most famous humor writer and lecturer in the United States in the second half of the 19th century after Mark Twain, although his reputation has not endured so well with later generations.
 
17 November 1864, Goshen (IN) Times, “Sayings of Josh Billings,” pg. 1, col. 8:
I argue this way, if a man is right, he kan’t be too radical, if he is wrong, he kan’t be conservative.
 
1 December 1864, Sullivan (IN) Democrat, pg. 4, col. 1:
Josh Billings says: “I argue in this way, if a man is right, he kan’t be too radical, if he is rong, he kan’t be too konservative.”
 
Chronicling America
29 May 1867, Western Reserve Chronicle (Warren, OH), pg. 2, col. 6:
(From the Columbus Journal.)
Radicalism.
“Radicalism means root-work; the uprooting of falsehoods and abuses,” says Dr. Robertson, and the definition furnishes such ample explanation of Democratic hostility to Radicalism, and its preference for the antipodal article, conservatism, that we became willing converts to the quaint creed of Josh Billings, that “when a man is right he can’t be too radical, and when he’s wrong he can’t be too conservative.”
   
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December 1867, The Friend, pg. 371:
Josh Billings says some good things, and here is one of them: “I am of opinion that if a man is right, he cannot be too radical, if he is wrong, he cannot be too conservative.”
 
Chronicling America
15 October 1869, The Conservative (M’Connelsville, OH), pg. , col. 5:
To Josh Billings, we are indebted for one sentence of wisdom, at least, to this effect: “If you are right, you can;t be too radical; and if wrong, too conservative.”
 
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A Handbook of Proverbs:
English, Scottish, Irish, American, Shakesperean, and Scriptural; and Family Mottoes
Edited by James Allan Mair
London: George Routledge and Sons
1873
Pg. 47:
If a man is right, he cannot be too radical; if wrong, he cannot be too conservative.  A. (American—ed.)
   
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March 1887, The Century Maazine, pg. 815:
Uncle Esek’s Wisdom.
(...)
If a man is right, he can’t be too radical; if wrong, he can’t be too conservative.
 
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Esar’s Comic Dictionary:
Completely revised and enlarged
By Evan Esar
New York, NY: Horizon Press
1951
Pg. 237:
right. (...) If a man is right, he cannot be too radical; if wrong, he cannot be too conservative.
 
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The New Speaker’s Treasury of Wit and Wisdom
By Herbert V. Prochnow
New York, NY: Harper
1958
Pg. 352:
RADICAL
If a man is right, he can’t be too radical; if he is wrong, he can’t be too conservative.  Josh Billings
 
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Uncle Sam’s Uncle Josh;
or, Josh Billings on practically everything, distilled from Josh’s rum-and-tansy New England wit
By Donald Day
Westport, CT: Greenwood Press
1972, ©1953
Pg. 171:
CONSERVATISM
Conservatism is a bag with a hole in it; radicalism is a hole with a bag in it.
 
If a man is right he can’t be too radical; if he is wrong, he can’t be too conservative.
 
All conservatives have once been radicals, and generally have more policy than principle.
 
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Peter’s Quotations:
Ideas for Our Time
By Dr. Laurence J. Peter
New York, NY: Quill
1993
Pg. 423:
If a man is right he can’t be too radical; if he is wrong, he can’t be too conservative. —Josh Billings (Henry Wheeler Shaw) (1818-1885)