I had given similar quotes as Nicholas J. Theocarakis, and our alert moderator
judiciously decided to not post it to avoid duplication (and thoughtfully informed me of his decision).
         
This is in response to Pat Inman's comments (approvingly?) that 
in it, Hudson writes, quoting Mill:
        
        > The sophistical tendency can be traced back to John Stuart Mill’s 
        > 1844 essay “On the Definition of Political Economy; and on the 
        > Method of Investigation Proper to it"...


I think Mill was far more sensitive to the reality of economic and social life to
leave the matter at that. In the essay he also writes:

Quote: Having now shown that the method a priori in Political Economy, and in all
other branches of moral science, is the only certain and scientific mode of
investigation, and that the a posteriori method, or that of specific experience, as
a means of arriving at the truth, is inapplicable to these subjects, we shall be
able to show that the latter method is notwithstanding of great value in the moral
sciences; namely, not as a means of discovering truth, but verifying it, and
reducing to the lowest point that uncertainty before alluded to as arising from the
complexity of every particular case, and from the difficulty (not to say
impossibility) of our being assured a priori that we have taken into account all
the material circumstances.

Mill's emphasis on disturbing causes as the reality check to abstract theory should
absolve him of the charge that he set economic theory on the path of airy
methodology. In my view, if economics as it developed after him had taken his ideas
more seriously, it would have taken a turn for the better. Deborah Redman (The Rise
of Political Economy as a Science, 1997) writes:

Quote: Disturbing causes in his view can be of two types. They may be causes not
yet discovered by political economists and, therefore, attributable to
circumstances that operate on human behavior through the principle of human nature
that distinguishes political economy as a science - that is, the desire for wealth.
Or they may be attributable to some other law of human nature, which means that
they fall outside the scope of political economy. In the latter case, "the mere
political economist, who has studied no science but Political Economy,...will fail
(Mill in the Essay, p. 331).

This is Mill's strong caveat against political economists spreading their abstract
theory as the gospel. In fact, as Sandra Peart and Samuel Hollander show in their
excellent article (JHET vol. 21, no. 4., 1999) Mill was in favor of not only
verification, but theory modification as well. That is what makes Mill a most
'reasonable' political economist.

Sumitra Shah