Marshall B. Rosenberg's Nonviolent Communication - A Language of Life is a book detailing how to communicate effectively with others in stressful or angry situations.

“Life-alienating communication both stems from and supports hierarchical or domination societies, where large populations are controlled by a small number of individuals to those individuals, own benefit. It would be in the interest of kings, czars, nobles, and so forth that the masses be educated in a way that renders them slavelike in mentality. The language of wrongness, should, and have to is perfectly suited for this purpose: the more people are trained to think in terms of moralistic judgments that imply wrongness and badness, the more they are being trained to look outside themselves—to outside authorities—for the definition of what constitutes right, wrong, good, and bad. When we are in contact with our feelings and needs, we humans no longer make good slaves and underlings.” - Marshall Rosenberg