"M: An argument isn't just contradiction.
A: It can be.
M: No it can't. An argument is a connected series of statements intended to establish a proposition.
A: No it isn't.
...
M: Argument is an intellectual process. Contradiction is just the automatic gainsaying of any statement the other person makes.
A: No it isn't" --from Monty Python's argument sketch
"DH3. Contradiction.
In this stage we finally get responses to what was said, rather than how or by whom. The lowest form of response to an argument is simply to state the opposing case, with little or no supporting evidence.
This is often combined with DH2 statements, as in:
I can't believe the author dismisses intelligent design in such a cavalier fashion. Intelligent design is a legitimate scientific theory.
Contradiction can sometimes have some weight. Sometimes merely seeing the opposing case stated explicitly is enough to see that it's right. But usually evidence will help." (http://www.paulgraham.com/disagree.html)