When the hearts of the many are hardened and are accepting of hate, it is then there will be woe among mankind and iniquity will prevail.
– Pioneer Lady

Gandhi described anger and intolerance as being the enemies of correct understanding, but they are also the enemies of reason.  They spread misunderstanding.

People will disagree on principles, or on the details of an issue, but that is not the same as standing on misinformation, calling it truth, and asserting all others are wrong in their beliefs.  Correct understanding therefor is not just the ability to understand, but the ability to understand the opposition and the ability to reason rather than simply rationalize.