Integrity
Integrity is a happy condition of mind where one's values, beliefs, and experiences are consonant (not dissonant). Perfect integrity is not possible for humans, but it is possible to strive individually for increased integrity.
The key to this striving is the active pursuit of cognitive dissonance, followed by remedial action (usually, adjustment of values). The highest integrity is to be found in individuals who have actively pursued every avenue which might end in rational persuasion, including avenues which lead to facts and ideas not of their liking. People with integrity are both jolly and grim. Grim, because they understand the difficulty. Jolly, because they can't do anything about it.
Cognitive castration, routinely administered by our school system to millions of our children, prevents the development of integrity, by fouling the individual's experience of cognitive dissonance and reducing it to a pointless shame ritual.