“Anger is the deepest form of compassion,” poet and philosopher David Whyte wrote in reclaiming the unseen dimensions of everyday words. “The internal living flame of anger always illuminates what we belong to, what we wish to protect and what we are willing to hazard ourselves for.” Anyone who has ever flared with anger at a loved one has brushed with this strange dissonance and knows it to be true on a most primal level. And yet we continue to judge — and especially to self-judge — only one side of anger, its destructive face, neglecting its paradoxical but profound constructive function as a mobilizing agent for our values.

That’s what the great Zen teacher Seung Sahn Soen-sa (August 1, 1927–November 30, 2004) explores in one of the many small doses of potent wisdom found in Only Don’t Know: Selected Teaching Letters of Zen Master Seung Sahn (public library).

In early November of 1976, Soen-sa received a distraught letter from one of his students, a woman named Diana, who had found herself consumed with anger at her son — “screaming mad … to the point that I even tried to slap him,” she wrote. The outburst was precipitated by a buildup of justified frustrations — the boy’s unchallenging academic environment, the troublemaker friends he had fallen with, his adamant resistance to moving to a more intellectually challenging school — and although her fury had come from a loving place of wanting to improve her son’s life, it plunged Diana into intense self-punishment and inconsolable sobbing. In addition to the distressing dissonance between the ugly surface turbulence of her temporary state and the deep love she felt for her son, she was particularly disoriented by how such anger could befall her just after she had attended three silent meditation retreats in the five weeks leading up to the incident.

She was turning to Soen-sa for advice and solace for her self-flagellation. Six days later, he responded with a nuanced and insightful letter of consolation, offering a taxonomy of the four types of anger and illuminating anger’s constructive face.

He writes:

After sitting yong maeng jong jin [silent meditation], your mind was clear. A clear mind is like a clear mirror, so when anger appeared, you reflected with angry action. You love your son, so you were angry. Is this correct? Don’t check your mind — when you are angry, be angry. When you are happy, be happy. When sad, be sad. Afterwards, checking is no good.

Your previous anger and the anger you talked about in your letter are different. Before yong maeng jong jin, it was attached anger; after yong maeng jong jin, your anger was only reflected anger. If you do more hard training, the reflected anger will change to perceived anger. After more practicing, perceived anger will disappear. Then you will have only loving anger — inside you will not be angry, only angry on the outside. So attached anger, reflected anger, perceived anger, loving anger — all are changing, changing, changing. Anger is anger; anger is the truth. Don’t worry, don’t check yourself — it has already passed. How you keep just-now mind is very important.

I have long believed that most constructive action comes as a form of complaint — an urge to effect positive change that arises out of dissatisfaction with the way things are and an active desire to steer them toward a more satisfying version. (A decade ago, I started Brain Pickings in large part out of dissatisfaction with my education, as an active complaint.) In a sense, Soen-sa paints anger as dissatisfaction in the extreme, which makes it a powerful mobilizing agent for positive change — or for what the great composer John Cage, a student of Zen himself, called constructive anarchy.

Soen-sa examines the rhythms of the four different kinds of anger as they course through us in succession, guided by Zen practice:

Attached anger sometimes lasts for three hours, sometimes three days, and does not quickly return to love-mind. When you were crying, you had reflected anger; it did not last long. Soon you returned to your mind that loves your son, and you knew what to do to help him… After more hard training, your reflected anger will change to perceived anger. You will feel anger but not show it; you will be able to control your mind. Finally, you will have only loving anger, ager only on the outside to hep other people — “You must do this!” — but no anger on the inside. This is true love-mind.

He ends with a note of assurance that the decision toward which the shock of Diana’s anger steered her — to move her son to a better school — was the right one and reflects a larger principle of personal growth:

Buddha said, “If one mind is pure, your world will be pure. Your world means your family, your friends, your country — all of them. So changing your son’s school is a very good idea. Sometimes, when the situation is bad, everything is bad; when the situation changes, then it is possible to change everything.

Complement this particular fragment of the wholly illuminating Only Don’t Know with philosopher Martha Nussbaum on anger and forgiveness and Alain de Botton on anger and the paradoxical psychology of sulking, then revisit Soen-sa on the three principles of Zen mind and his soulwarming response to hate mail.