Coined by C.S. Lewis in his essay, First and Second things.
The act of assuming without discussion that a person is wrong and then distracting his or her attention from this (the only real issue) by builsy explaining why he or she is wrong and how that person became so silly.
"There flashed across my opening mind the great truth that refutation is no necessary part of argument. Assume that your opponent is wrong, and then explain his error, and the world will be at your feet. Attempt to prove that he is wrong or (worse still) try to find out whether he is wrong or right, and the national dynamism of our age will thrust you to the wall." That is how Bulverism became one of the makers of Twentieth Century