Ahimsa means non-injuring, non-hurting, and non-killing. Normally, students think of violence in only physical terms, and civilized people refrain from gross acts of violence because of legal and social pressures. But ahimsa refers to non-violence in thought, action, and speech. All actions and speech are directed by the mind. Therefore, violence in action or speech is always preceded by violent thoughts.
-- Swami Rama