Coaster

If the reader asks how this is, I reply that it is simply the
natural baseness of human nature. If human nature were not base, but
thoroughly honourable, we should in every debate have no other aim
than the discovery of truth; we should not in the least care whether
the truth proved to be in favour of the opinion which we had begun by
expressing, or of the opinion of our adversary. That we should
regard as a matter of no moment, or, at any rate, of very secondary
consequence; but, as things are, it is the main concern. Our
innate vanity, which is particularly sensitive in reference to our
intellectual powers, will not suffer us to allow that our first
position was wrong and our adversary's right. The way out of this
difficulty would be simply to take the trouble always to form a
correct judgment. For this a man would have to think before he spoke.
But, with most men, innate vanity is accompanied by loquacity and
innate dishonesty. They speak before they think; and even though they
may afterwards perceive that they are wrong, and that what they assert
is false, they want it to seem the contrary. The interest in truth,
which may be presumed to have been their only motive when they stated
the proposition alleged to be true, now gives way to the interests of
vanity: and so, for the sake of vanity, what is true must seem false,
and what is false must seem true.