Gandhi called his method of political action Satyagraha -- a word he devised from two others and translated into English roughly as "soul-force" or "Truth-force." A more exact rendering might be "the force that is generated through adherence to Truth."
Outside India today, this method of Gandhi's is popularly called nonviolence. But Gandhi had a different use and meaning for the English word nonviolence, and the word he translated it from was different: ahimsa. This Hindu term normally means "a way of acting that refrains from hurting others." For Gandhi it came to mean a way of life based on love or compassion for all.
To Gandhi, then, Satyagraha was not the same as non- violence but an outgrowth of it. In this book, Gandhi's distinction between the two concepts is preserved.
For Western readers, though, Satyagraha is too exotic a term for regular use. Other attempted substitutes over the years have included passive resistance -- a term Gandhi used at first, then rejected -- nonviolent resistance, nonviolent direct action, nonviolent action, and, most recently, active nonviolence. Following chapter 1, this book uses nonviolent action throughout.
But the equivalence of this substitute, as of the others, is only rough. Nonviolent action -- in this book as elsewhere -- can refer to any aggressive, purposeful action that refrains from physically harming the opponent. But, as chapter 1 describes, the type of nonviolent action that is Satyagraha goes much farther toward embodying nonviolence in Gandhi's sense.