So true. I have witnessed many who will denigrate anyone who disagrees with their tightly-held beliefs, or identities as she refers to them, rather than seeking the truth. They feel that anyone who argues against their belief is attacking them directly, even though no personal remarks or insults were made. At the same time, those taking the opposite view may overstate their case as the absolute truth, preventing them from engaging in honest discourse over the subject.
Instead of holding firmly to ones own beliefs, she suggests actively seeking the truth - even if it opposes your own belief(s).