" Under stress, an unexercised heart will explode in frustration or fury. If the situation is especially tense, that exploding heart may be hurled like a fragment grenade toward the source of its pain. But a heart that has been consistently exercised through conscious engagement with suffering is more likely to break open instead of apart. Such a heart has learned how to flex to hold tension in a way that expands its capacity for both suffering and joy. "

― Parker J. Palmer , Healing the Heart of Democracy: The Courage to Create a Politics Worthy of the Human Spirit