The economist John Maynard Keynes (1883-1946) wrote in his book, A Tract on Monetary Reform (1923):
 
“In truth, the gold standard is already a barbarous relic.”
 
The term “barbarous relic” soon became applied to gold as well as the gold standard. In the 2000s, as the price of gold steadily increased, the term “barbarous relic” was used with some irony.
 
Although Keynes is credited with calling the gold standard a “barbarous relic,” many other people had written similar terms (“gold is a relic of barbarism”) well before 1923. John Austin Stevens wrote to the New York (NY) Times in October 1873, stating that “gold is a relic of barbarism to be tabooed by all civilized nations.” Tennessee merchant John T. Goss testified before the U.S. Senate in 1894, saying that “Gold is a relic of barbarism and should be discarded by all civilized nations as a medium of exchange.” The book Civilized Money (1895), by Charles M. Howell, also declared that “gold is a relic of barbarism.” In December 1921, Thomas Edison said that ““Gold is a relic of Julius Caesar and interest is an invention of Satan.”

Gold has also been called an “anti-dollar,” a “currency of last resort,” a “pet rock” and a “yellow dog.”
 
   
Wikipedia: John Maynard Keynes
John Maynard Keynes, 1st Baron Keynes CB FBA ( /ˈkeɪnz/ kaynz; 5 June 1883 – 21 April 1946), was a British economist whose ideas have profoundly affected the theory and practice of modern macroeconomics, as well as the economic policies of governments. He greatly refined earlier work on the causes of business cycles, and advocated the use of fiscal and monetary measures to mitigate the adverse effects of economic recessions and depressions. His ideas are the basis for the school of thought known as Keynesian economics, as well as its various offshoots.
 
In the 1930s, Keynes spearheaded a revolution in economic thinking, overturning the older ideas of neoclassical economics that held that free markets would in the short to medium term automatically provide full employment, as long as workers were flexible in their wage demands. Keynes instead argued that aggregate demand determined the overall level of economic activity, and that inadequate aggregate demand could lead to prolonged periods of high unemployment. Following the outbreak of World War II, Keynes’s ideas concerning economic policy were adopted by leading Western economies. During the 1950s and 1960s, the success of Keynesian economics resulted in almost all capitalist governments adopting its policy recommendations, promoting the cause of social liberalism.
 
13 January 1869, Cincinnati (OH) Daily Gazette, pg. 2:
THE BUTLER CURRENCY PLAN.
BENJAMIN F. BUTLER has brought forward a currency plan, and advocated it in a speech at much length, which we publish in this paper. Mr. BUTLER escapes all the hardships of a return to specie payment by cutting loose from specie altogether, and soaring to the upper plane of a perpetually irredeemable currency. He pronounced gold and silver money a relic of barbarism, like those political twin sisters slavery and polygamy. He condemns coined money as the badge of popular servitude and of despotic rule. He thinks that our wise constitutional fathers made a grave mistake that they did not abolish the use of gold and silver as money, and that thereby they endangered the liberties of the people. He argues that we should no more use the same kind of money that nations having monarchical governments use than we should use their institutions of kings and crown and hereditary nobility. He alleges, also, that the savage tribes, the barbarous and semi-barbarous nations, and even the Chinese, use gold and silver money, which is positive proof that it is unfit for civilized peoples.
     
Google Books
Resumption of Specie Payment.
A series of letters to the New-York Daily Times.
By John Austin Stevens
New York, NY: J.W. Amerman, Printer
1873
Pg. 22.
8 October 1873, New York (NY) Times, “Gradual Resumption,” pg. 4:
To the Editor of the New-York Times:
(...)
The measure of values is the circulating medium of a country—the values so measured rise or fall, as the measure itself is enlarged or lessened. Gold is only a standard as it is used as a standard. Were it not for our intercourse with foreign nations we should have no use for it except in the arts, and Gold Boards and Sub-Treasuries would be needless. But as yet the European and Asiatic nations have not adopted the last American conception that gold is a relic of barbarism to be tabooed by all civilized nations, and they still insist on payment in gold for the balance of account between their sales to us and our purchases from them.
(...)
KNICKERBOCKER.
     
Google Books
The Yanko-sequor
A work in two books, independent of each other.
Book II. Disquisitions upon the ways to arrive at the demonetization of gold and silver, and upon the establishment of private banks under the control of a national government
By Martin Regul Pilon
New York, NY: Authors’ Pub. Co.
1875
Pg. 169:
In reality money is neither a gold coin nor the so-called paper money — the first is a relic of barbarism, the last is a shift that was fallen upon by society; when dismayed at seeing the paucity of precious metals to furnish for all its needs, and particularly for that of currency, took unconsciously to look out for substitutes, and then had recourse to paper money.
   
Google Books
Paper Money, the Money of Civilization.
An issue by the state, and a legal tender in payment of taxes.
By James Harvey, of Liverpool
London: Provost & Co.
1877
Pg. 221:
The love of gold is, in fact, a relic of barbarism, only worthy of half-civilized orientals.
 
Google Books
The Republican Manual:
History, principles, early leaders, achievements of the Republican Party : with biographical sketches of James A. Garfield and Chester A. Arthur
By Eugene Virgil Smalley
New York, NY: American Bk. Exchange
1880
Pg. 82:
Gold and silver money was a relic of barbarism, they declared; to use valuable metals for currency when paper, which cost next to nothing, would answer the purpose much better, being wasteful and foolish.
   
Google Books
Whither Are We Drifting as a Nation
By Freeman Otis Willey
St. Louis, MO: G.C. Hackstaff
1882
Pg. 444:
The idea that gold is a standard of value for other commodities is a relic of barbarism.
 
Google Books   
Addresses, Speeches, Lectures, and Letters Upon Various Subjects
By Hugh McCulloch
Washington, DC: W.H. Lepley
1891
Pg. 173:
Gold and silver coins, instead of being what some of the inflationists in Ohio call them—“a relic of barbarism”—are the great financial regulator of commercial nations, indicating by their movements unerringly when a nation is going too fast and putting on the check before the movements become dangerous.
 
Google Books
BULLETIN No. 56, PART II.
COMMITTEE ON FINANCE. UNITED STATES SENATE.
REPLIES TO TARIDD INQUIRIES.
NUMBERS 7425 TO 7818.
AUGUST 28, 1894.—Ordered to be printed.
Washington, DC: Government Printing Office
1895
Pg. 144 (Replies of Merchants):
TENNESSEE
No. 7679.
John T. Goss, general merchandise, Deer Lodge.
(...)
Gold is a relic of barbarism and should be discarded by all civilized nations as a medium of exchange, for the reason that it is too scarce and consequently too dear. Every dollar that it represents in value has probably cost fifty or a hundred in labor to produce it from the mines, and it is so scarce tjhat it is easily controlled by individuals and corporations. What we need is an elastic currency issued direct by the Government.
 
Google Books
Civilized Money:
The way to prosperity, happiness, civilization
By Charles M. Howell
Grand Rapids, MI: Cash Pub. Co.
1895
Pg. 166:
THE SPEAKER: You speak of “civilized money;” what is “civilized money?” and why do you call it that?
UNCLE SAM: It is a medium of exchange that will, without exception, produce civilization. Has gold ever done that? Gold is a relic of barbarism, and has held every people who have adopted it as a standard in, or degraded them to, a condition of barbarism. Gold is the talisman that, without exception, turns men aside from the path of progression and good to the power of Mammon. It was so in ancient times; it has been so all along down the path, and is so now.
   
Google Books
The Present Status of Socialism in America
By Jessie Wallace Hughan
New York, NY: Cambridge, University Press
1911  
Pg. 147:
In popular pamphlets we may still see allusions to gold money as the “yellow relic of barbarism,” and to the certificate of value equal to the product of the worker, but the creators of Socialist thought in Europe and America have definitely repudiated them.
 
24 July 1918, Omaha (NE) World-Herald, pg. 7, col. 3:
War Finance and Gold.
(St. Louis Post-Dispatch.)
“Will gold currencies be discarded?” asks Arthur Selwyn-Brown in the current number of the Journal of the American Bankers’ association.
 
No new point is raised by the question itself. It was one that figured constantly in the intensive public discussion on the financial question two decades or more ago. Scientific these on money then held that the exaggerated value attached to gold is a relic of barbaric days, that its scarcity renders it a rather insecure basis for the colossal financial fabric of the world, and that a medium of exchange, or money, based on credit would have greater stability and many other features of superiority, provided it was given common recognition by the commercial nations.
 
6 December 1921, New York (NY) Times, “Ford Sees Wealth in Muscle Shoals,” pg. 6:
“Make it perfectly clear that I’m not advocating any changes in banks and banking,” said Mr. Edison. “Banks are a mighty good thing. They are essential to the commerce of the country. It is the money broker, the money profiteer, the private banker, that I oppose. They gain their power through a fictitious and false value given to gold.
 
“Gold is a relic of Julius Caesar and interest is an invention of Satan,” Mr. Edison continued. “Gold is intrinsically of less utility than most metals. The probable reason why it is retained as the basis of money is that it is easy to control. And it is the control of money that constitutes the money question. It is the control of money that is the root of all evil.”
 
Google Books
July 1922, Machinists’ Monthly Journal, pg. 471, col. 2:
The Dollar, What Is It?
By J. WELLER LONG
(...)
Tbjs substitutes a scientific, up-to-date system for the present antiquated relic of barbarism, the so called “gold standard” humbug and fraud.
 
Google Books
A Tract on Monetary Reform
By John Maynard Keynes
London: Macmillan and Co., Limited
1923
Pg. 187:
In truth, the gold standard is already a barbarous relic.
 
30 March 1924, New York (NY) Times, pg. BR3:
Mr. Keynes on the Mysteries of American Finance
The Gold Standard “a Barbarous Relic,” and Other Opinions in His “Monetary Reform”
A Review by
ALEXANDER DANA NOYES
MONETARY REFORM. By John Maynard Keynes. 277 pp. New York: Harcourt, Bruce & Co.
(...)
In no respect is this habit of mind more evident than in this book’s remarks upon the gold standard itself. That standard is a “barbarous relic,” an “outworn dogma.” It “had its value once,” but now it is “remote from the spirit and requirements of the age.” If it could be restored, it would mean “that we surrender the regulation of our [England’s] price level and the handling of the credit cycle to the Federal Reserve Board of the United States” (page 189(. We shall see that his dislike of that board and its policies warps his economic judgment as completely as does his angry feeling against the gold standard itself.
     
OCLC WorldCat record
Gold barbarous relic or useful instrument?
Author: Miroslav A Kriz
Publisher: Princeton, NJ Intern. Finance Section, Dep. of Economics, Princeton Univ. 1967
Series: Essays in international finance, 60. 
Edition/Format:  Book : English
 
OCLC WorldCat record 
The rise and fall of a barbarous relic : the role of gold in the international monetary system
Author: Michael D Bordo; Barry J Eichengreen
Publisher: Cambridge, Mass. : National Bureau of Economic Research, 1998.
Series: NBER working paper series, 6436. 
Edition/Format:  Book : English
 
Barbarous Relic (blog)
Exposing the fraud of fiat money and central banking
 
LewRockwell.com
February 28, 2009
Gold: The Barbarous Relic You Can Trust
by Bill Bonner
 
Business Insider
Roubini: Here’s Five Reasons The “Barbarous Relic” Gold Is Going To Tank
Joe Weisenthal | Dec. 14, 2009, 6:30 AM
 
Zero Hedge
Update: $1,623 And Rising….. The “Traditional” “Barbaric Relic” Hits An All Time High Of Over $1615
Submitted by Tyler Durden on 07/24/2011 18:24 -0400
Here, let us explain to you how this works: you take some “tradition”, you mix some central planning, you throw the imminent threat of default by the world’s reserve currency and you end up with gold surging to $1615, well on its way to $10,000 and more. Any questions?