It seems that the major fallacy is other people's theories. Mason Gaffney  
may be sarcastic but he is also correct.  
  
Thus Knight writes under the heading "The Major Fallacy of the Political  
Economists":  
"Pivotal, as the fountainhead of analytical fallacy, was an apparent mental  
fixation on labor as alone really productive.", "Economic History", in P.  
Wiener (ed.), The Dictionary of the History of Ideas, 1973-4, vol. 2, p. 48  
  
Ludwig von Mises writes  (Human Action: A Treatise On Economics, 1963  
[1949], pp. 203-4):  
  
  
An inveterate fallacy asserted that things and services exchanged are of  
equal value. Value was considered as objective, as an intrinsic quality  
inherent in things and not merely as the expression of various people's  
eagerness to acquire them. People, it was assumed, first established the  
magnitude of value proper to goods and services by an act of measurement and  
then proceeded to barter them against quantities of goods and services of  
the same amount of value. This fallacy frustrated Aristotle's approach to  
economic problems and, for almost two thousand years, the reasoning of all  
those for whom Aristotle's opinions were authoritative. It seriously  
vitiated the marvelous achievements of the classical economists and rendered  
the writings of their epigones, especially those of Marx and the Marxian  
school, entirely futile. The basis of modern economics is the cognition that  
it is precisely the disparity in the value attached to the objects exchanged  
that results in their being exchanged.  
  
Of course, it is quite reasonable, that scientists should expose fallacies.  
Most arguments are based on that.  If you do your searches you can find the  
concept very early in economics. [E.g., in the mercantilists (Misselden in  
Free Trade, Dudley North "All which is a profound Fallacy, and hath been a  
Remora, whereby the growing Wealth of many Countries have been obstructed"  
in Discourses, etc.). I googled on Rod Hay's site].  
  
Indeed the sweet and always well meaning J.S. Mill asserts that being open t  
o accept your fallacy is the only way forward (On Liberty, ch ii):  
  
"The whole strength and value, then, of human judgment, depending on the one  
property, that it can be set right when it is wrong, reliance can be placed  
on it only when the means of setting it right are kept constantly at hand.  
In the case of any person whose judgment is really deserving of confidence,  
how has it become so? Because he has kept his mind open to criticism of his  
opinions and conduct. Because it has been his practice to listen to all that  
could be said against him; to profit by as much of it as was just, and  
expound to himself, and upon occasion to others, the fallacy of what was  
fallacious. Because he has felt, that the only way in which a human being  
can make some approach to knowing the whole of a subject, is by hearing what  
can be said about it by persons of every variety of opinion, and studying  
all modes in which it can be looked at by every character of mind. No wise  
man ever acquired his wisdom in any mode but this."  
  
The question is rather, do we reject other theories for truly "internal"  
reasons, or do we masquerade political arguments as "logical fallacies"?  
  
Nicholas J. Theocarakis