words the law of
contradiction is itself the crowning point of absurdity." To which
Engels replies as follows):

The thought content of the foregoing passages is contained in the
statement that contradiction is an absurdity and cannot occur in the
actual world. This statement will have for people of average common
sense the same self-evident truth as to say that straight cannot be
crooked nor crooked straight. But the differential calculus shows in
spite of all the protests of common sense that under certain
conditions straight and crooked are identical, and reaches thereby a
conclusion which is not in harmony with the common sense view of the
absurdity of there being any identity between straight and crooked.
Considering moreover the significant role which the so called
Dialectic of the Contradiction played in the ancient Greek philosophy,
a stronger opponent than Herr Duehring would be obliged to meet it
with better arguments than a mere affirmation and a number of
epithets.

As long as we regard things as static and without life, each by
itself, separately, we do not run against any contradictions in them.
We find certain qualities sometimes common, sometimes distinctive,
occasionally contradictory, but in this last case they belong to
different objects and are hence not self contradictory. While we
follow this method we pursue the ordinary metaphysical method of
thought. But it is quite different when we consider things in their
movement, in their change, their life and their mutually reciprocal
relations. Then we come at once upon contradictions. Motion is itself
a contradiction since simple mechanical movement from place to place
can only accomplish itself by a body being at one and the same moment
in one place and simultaneously in another place by being in one and
the same place and yet not there. And motion is just the continuous
establishing and dissolving the contradiction.

Here we have a contradiction which is "objective, and so to speak
corporeal in things and events." And what does Herr Duehring say about
it? He affirms that "in rational mechanics there is no bridge between
the strictly static and the dynamic." Finally the reader is able to
see that there is behind this pretty little phrase of Herr Duehring
nothing more than this--that the metaphysical mode of thought can
absolutely not pass from the idea of rest to that of motion because
the aforesaid contradiction intervenes. Motion is absolutely
i