The aspirant should establish mastery over the external senses. Then, the mind, immersed in the continuous succession of subject-object (vishaya) relationship, has to be controlled by means of peace (shanti) and renunciation (vairagya). When that is done, one can experience real spiritual bliss (ananda) and visualise the Atma, in its real form. That is why Krishna once told Arjuna, “Those who aspire to have mastery over the senses must have full faith in Me.” The senses are always extroverted in nature; they are greedy for external contacts. Therefore, they drag the ignorant perpetually toward external objects. So the spiritual aspirant, endowed with discrimination and renunciation, must place obstacles in their outward path and suppress their outbursts, just like what the charioteer, wielding the whip and the reins, does to the raging steeds. Uncontrolled senses cause great harm. People in their grip cannot engage themselves in meditation, even for a single second! (Dhyana Vahini, Ch 13)