In the OP, Friedman is quoted as writing:
“Think that through and he [Rothbard] was saying that it was all right to misrepresent the evidence to his fellow libertarians as long as the result was to make them think badly of someone they should think badly of, to lead them to the correct conclusion for the wrong reason. I don’t regard that as a desirable approach to political (or other discussion). Or, for that matter, a libertarian one—we are generally opposed to fraud as well as force.”
Rothbard used this tactic in arguing against free banking in his paper “The Present State of Austrian Economics” (A Working Paper from the Ludwig von Mises Institute, November 1992).
Here are the passages in question, pages 35 and 36. Rothbard is arguing that to advocate free banking is to advocate conterfeiting, and he implies that this is Mises’s position as well:
“What is desperately needed is to abolish the counterfeiting. That was the proposal stemming from Mises’s insight into the inevitably destructive effects of paper money and fractional reserve banking. Instead, what our pseudo-Austrian economists propose to do is not to abolish counterfeiting, but to privatize it—to open up the counterfeiting process to “free” private competition.”
“One of Mises’s favorite quotes on money and banking was from Thomas Tooke: “free trade in banking is tantamount to free trade in swindling.” Tooke and Mises, of course, were referring to fractional-reserve banking, in which banks pledge to redeem on demand receipts to non-existent money in their vaults. These bank notes or deposits are just as much counterfeit as warehouse receipts to non-existent grain,…”
“The champions of free competition in counterfeiting retort that this is simply the market at work…”
“If counterfeiting per se is deplorable and to be outlawed, then the same standards must be applied to its surrogate, fractional reserve banking, which is currently legal and which would run rampant in the “free-banking” heaven of our non-Misesian pseudo-Austrians.”
Rothbard writes that one of Mises’s favorite quotes was “free trade in banking is tantamount to free trade in swindling.” But he neglects to mention that Mises strongly disagreed with this quote.
Rothbard writes that to advocate free banking is to be a “non-Misesian pseudo-Austrian.” However, Mises was a free-banking advocate.
“It is a mistake to associate with the notion of free banking the image of a state of affairs under which everybody is free to issue banknotes and to cheat the public ad libitum. People often refer to the dictum of an anonymous American quoted by Tooke: “Free trade in banking is free trade in swindling.” However, freedom in the issuance of banknotes would have narrowed down the use of banknotes considerably if it had not entirely suppressed it.” (Human Action, 3rd rev. ed. p.446)
Above, Mises argues for free banking and against Tooke’s dictum.
Mises’s position on free banking and Tooke’s dictum is also recorded in the book “The Free Market and Its Enemies.” This book is a transcription of some talks Mises gave in 1951.
“Propagandists who wanted to make the government pre-eminent in the issuance of money substitutes have publicized many stories about private money substitutes. These tales were condensed by an anonymous American who is credited with the dictum “Free trade in banking is free trade in swindling.” Economists, however, think differently; they consider free trade in banking as the only protection against the government’s issuance of bad banknotes.” (p.63)
Above, Mises again takes issue with Tooke’s dictum and advances the case for free banking.
Mises reiterates:
“The defenders of government interference with the issuance of banknotes and checkbook money justify this policy by declaring that “free trade in banking is free trade in swindling.” The poor, ignorant people must be protected, they say, against bad banknotes. But no one would be forced to take banknotes if they had not been declared legal tender by the government.” (p.81)
Again, Mises takes issue with Tooke’s dictum and argues in favor of free banking.
One who reads Rothbard’s article and who is unfamiliar with Mises’s position on free banking will come away believing that Mises quoted Tooke favorably and that Mises was against free banking, when the opposite is the case.
This is what Friedman means in writing:
“[Rothbard] was saying that it was all right to misrepresent the evidence to his fellow libertarians as long as the result was to make them think badly of someone they should think badly of, to lead them to the correct conclusion for the wrong reason. I don’t regard that as a desirable approach to political (or other discussion). Or, for that matter, a libertarian one—we are generally opposed to fraud as well as force.”