Mahatma Gandhi said this quote

most Americans think of Rosa Parks as a demur, pleasant-enough seamstress who backed into history by being too tired to get out of her seat on a bus one day, in reality she had been trained in nonviolence spirit and tactics at a famous institution, Highlander Folk School. It seems to be a difficult concept for most of us that peace is a skill that can be learned. We know war can be learned, but we seem to think that one becomes a peacemaker by a mere change of heart. (23)