For the spiritual scientist, anger is also the harbinger of something quite different. Life shows us that a person who is unable to flare up with anger at injustice or folly will never develop true kindness and love. Equally, a person who educates himself through noble anger will have a heart abounding in love, and through love he will do good. Love and kindness are the obverse of noble anger. Anger that is overcome and purified will be transformed into the love that is its counterpart. A loving hand is seldom one that has never been clenched in response to injustice or folly. Anger and love are complementary.
Transmuted anger is love in action. That is what we learn from reality. Anger in moderation has the mission of leading human beings to love; we can call it the teacher of love.
Source: Rudolf Steiner – Ga 58 – Metamorphoses of the Soul Paths of Experience Vol. 1 – Lecture 2: The Mission of Anger – Munich, 5th December, 1909
Translated by C. Davy and C. von Arnim