Take the example of someone getting angry at you for no reason. For a normal person it is difficult to remain calm and undisturbed in such a situation. But you should use your discrimination in order to keep your mind well under control. For this to happen, introspection is needed. To accept the anger as a blessing sent by the Lord in order to test your patience, or to ignore and remain unaffected, one needs sharp discrimination. In both cases a sadhak (seeker) must make a conscious and continuous effort in order to proceed towards the ultimate goal.