In any nonviolent campaign there are four basic steps: collection of the facts to determine whether injustices exist; negotiation; self-purification; and
from Martin Luther King, Jr – Letter From Birmingham Jail on Rap Genius
Meaning

Dr. King was a student of peaceful protests. This ideology was presented to him by Bayard Rustin, who was a mentor of sorts. Nonviolent protests at its foundation were ways to express displeasure through peace.
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