Are they about science? Are they about theology?
I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it be such as would oblige them to admit the falsity of conclusions which they have delighted in explaining to colleagues, which they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives.
It is really quite amazing by what margins competent but conservative scientists and engineers can miss the mark, when they start with the preconceived idea that what they are investigating is impossible. When this happens, the most well-informed men become blinded by their prejudices and are unable to see what lies directly ahead of them.
Arthur C. Clarke, 1963
Only a fool of a scientist would dismiss the evidence and reports in front of him and substitute his own beliefs in their place.
The high-minded man must care more for the truth than for what people think.
I found those quotes here, while looking for some fun quotes along those lines for an essay I'm writing.