SB 2.1.18

The first process of spiritualizing the mind by mechanical chanting of the pranava omkara and controlling the breathing system is technically called the mystic or yogic process of pranayama, or fully controlling the breathing air. The ultimate state of this pranayama system is to become fixed up in trance, technically called the stage of samadhi. But experience has proven that even the samadhi stage also fails to control the materially-absorbed mind. For example, the great mystic Visvamitra Muni, even in the stage of samadhi, became a victim of the senses and cohabited with Menaka. History has already recorded it. The mind, although ceasing to think of sensual activities at present, remembers past sensual activities from the subconscious status and thus disturbs one from cent per cent engagement in self-realization. Therefore, Sukadeva Gosvami recommends the next step of assured policy, namely to fix one's mind in the service of the Personality of Godhead. Lord Sri Krsna, the Supreme Personality of Godhead, also recommends this direct process in the Bhagavad-gita (Bg. 6.47). Thus, the mind being spiritually cleansed, one should at once engage himself in the transcendental loving service of the Lord by the different devotional activities of hearing, chanting, etc. That is the surest path of progress even for the disturbed mind, if performed under proper guidance.