After extended thought, I don’t think this needs to be long. Confirming evidence for our beliefs is more central than disconfirming evidence. That is, we can withstand a great deal of evidence which calls our beliefs into question, so long as there is some continuous amount of evidence which supports them. Beliefs erode not because they are mortally wounded, but because they are undernourished. Exceptions occur, but this is the general tendency of humanity.
As this becomes more pronounced, it reveals itself as pathological. Delusions, impervious to all contrary evidence, persist in their tight circles of logic. I have been most concerned with this phenomenon in political, social, and religious thought. I am most familiar with this in my line of work, listening to mentally ill people on an individual level evade obvious realities for the sake of preserving a single interpretation. But there is a strong need to believe certain principles in every culture, and confirming evidence will be found even if it involves turning the data back in the opposite direction. I have been something of a counter-cultural warrior, arguing that the main danger to our culture comes not from the tight circles of logic on the side of simple faith, simple patriotism, and simple civic morality, but from the even tighter circles of our enlightened classes which seek to undermine these.
There are closed circles on both sides, of course. But far more often than is commonly believed, it is the dogmatic who are ultimately tolerant; those who believe themselves tolerant are always in peril that a deeper dogmatism is disguised within them. Those who know they rely ultimately on faith apply reason forcefully nonetheless; those who claim to rely only on reason conceal a hundred unquestioned creeds from their own sight.