I thought this was nicely put:

You must show that a man is wrong before you start
explaining why he is wrong. The modern method is to assume without
discussion that he is wrong and then distract his attention from this
(the only real issue) by busily explaining how he became so silly.

In the course of the last fifteen years I have found this vice so
common that I have had to invent a name for it. I call it “Bulverism”.
Some day I am going to write the biography of its imaginary inventor,
Ezekiel Bulver, whose destiny was determined at the age of five when he
heard his mother say to his father — who had been maintaining that two
sides of a triangle were together greater than a third — “Oh you say
that because you are a man.” “At that moment”, E. Bulver assures us,
“there flashed across my opening mind the great truth that refutation is
no necessary part of argument. Assume that your opponent is wrong, and
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 Bulver became one of the makers of the Twentieth
Century.

[…]

Suppose I think, after doing my accounts, that I have a large balance
at the bank. And suppose you want to find out whether this belief of
mine is “wishful thinking.” You can never come to any conclusion by
examining my psychological condition. Your only chance of finding out is
to sit down and work through the sum yourself. When you have checked my
figures, then, and then only, will you know whether I have that balance
or not. If you find my arithmetic correct, then no amount of vapouring
about my psychological condition can be anything but a waste of time. If
you find my arithmetic wrong, then it may be relevant to explain
psychologically how I came to be so bad at my arithmetic, and the
doctrine of the concealed wish will become relevant — but only after you
have yourself done the sum and discovered me to be wrong on purely
arithmetical grounds. It is the same with all thinking and all systems
of thought. If you try to find out which are tainted by speculating
about the wishes of the thinkers, you are merely making a fool of
yourself. You must first find out on purely logical grounds which of
them do, in fact, break down as arguments. Afterwards, if you like, go
on and discover the psychological causes of the error.

From the comments on:
https://slatestarcodex.com/2019/07/17/caution-on-bias-arguments/