Renunciation is the translation of the Sanskrit term aparigraha, (non-grasping). Renunciation was one of cardinal principles for residents of Gandhi’s ashrams. This attitude of renouncing personal attachment to anything — an object, another person, even an idea or opinion — is the key to self mastery, and also the spiritual key to freedom from coercion by others. If you desire something for yourself alone, that desire will control you, and others will be able to control you by threatening to withhold or take what you desire. If you renounce the desire, you unleash your own capacity to act in freedom, including the capacity to act nonviolently. This dynamic can be paraphrased as ― ask yourself what they are holding over you; renounce that, and you are free.
As an example, when Daniel Ellsberg was deciding what to do with the Pentagon Papers, he was at first paralyzed by anxiety about what would happen to him if he made them public. At some point it occurred to him to ask himself, If I were willing to go to jail, what might I do with them? He realized the answer to his question was that by renouncing his own freedom he would then be free to release the papers.
In the extreme, if you renounce attachment to your physical body, the threat of violence loses its power. To quote Albert Szent-Gyeorgyi, “[Gandhi] taught the world that there are higher things than force, higher even than life itself; he proved that force had lost its suggestive power.”