A: the earth is flat
B: I dispute your premise.
A: The evidence clearly shows that the earth is flat .
B: the earth is self-evidently not flat .
A: The evidence clearly shows that the earth is flat .
B: It is clearly not true that the earth is flat .
A: Sir, you are a buffoon.
B: You're quite wrong, all llamas are stripy
A: I dispute your premise.
B: Sir, you are a buffoon.
A: Isn't that a non sequitur?
MoonShadow/FlameWar