ultivate more barley nor can I differentiate and integrate,
just as I cannot play the violin by virtue of a mere knowledge of the
laws of harmony. But it is evident that a merely childish negation of
the negation such as writing down a and erasing it, or by affirming
that a rose is a rose and that it is not a rose leads to no conclusion
other than to show the silliness of the people who undertake processes
so tedious. And yet metaphysicians would inform us that that is the
right way to carry out the negation of the negation.

Herr Duehring is therefore a mystifier when he asserts that the
negation of the negation was an analogy made by Hegel derived from
religion and built up on the story of the Fall and the Redemption. Men
thought dialectically a long time before they knew what the dialectic
really was, just as they spoke prose a long time before the term
"prose" was used. The law of the negation of the negation which
operates in history and which until it is once learned goes on in our
brains unconsciously to ourselves, was first clearly formulated by
Hegel, and if Herr Duehring desires to employ it in secret but cannot
stand the name, he should discover a better name. But if he insist on
expelling it from the processes of thought, he must first be good
enough to expel it from nature and from history, and find a system of
mathematics in which --a multiplied by --a does not give us + a^2 and
where the differential and integral calculus are both forbidden by
law.

_Conclusion._

In this short section Engels leaves the general discussion in order to
again pay his respects to the shortcomings and deficiencies of Herr
Duehring. The matter possesses no general interest for Engels merely
teases his opponent upon the magnificence of his claims and the
slightness of his performances.

PART II

CHAPTER VIII

POLITICAL ECONOMY

_I. Objects and Methods._

Political economy is, in the widest sense, the science of the laws
controlling the production and exchange of the material necessities of
life in human society. Production and exchange are two entirely
different functions. Production may exist without exchange,
exchange--since there can only be exchange of products--cannot exist
without production. Each of the two social functions is controlled by
entirely different external influences and thus has, generally
speaking, its own peculiar laws. But on the other hand they become so
mutually involved at a