In the dictionary of the seeker of truth there is no such thing as being "not successful." He is or should be an irrepressible optimist because of his immovable faith in the ultimate victory of Truth, which is God.
How can one be compelled to accept slavery? I simply refuse to do the master's bidding. He may torture me, break my bones to atoms and even kill me. He will then have my dead body, not my obedience. Ultimately, therefore, it is I who am the victor and not he, for he has failed in getting me to do what he wanted done.
It is the acid test of nonviolence that in a nonviolent conflict there is no rancor left behind, and in the end the enemies are converted into friends.