2.66 In him who does not focus his mind on Me but is engaged only in the control of senses by his own exertion, the Buddhi or the right disposition that is concerned with the pure self never arises. Therefore he fails in the practice of meditation on the self. In one who cannot think of the pure self, there arises the desire for sense objects; in him serenity does not arise. How can eternal and unsurpassed bliss be generated in him who is not serene but is attached to sense-objects?  [The idea is that without the aid of devotion to God, the effort to control the senses by one's will power alone will end in failure.]

 Sri Krsna speaks again of the calamity that befalls one who does not practise the control of the senses in the way prescribed above: