IF THE WORLD IS DARK TO A SEER, THEN HOW  DOES HE LIVE IN THE WORLD?

aapooryamaanam  achalapratishtham
    samudram  aapah pravishanti yadwat
    tadwat  kaamaa yam pravishanti sarve
    sa  shaantim aapnoti na kaamakaami // 2.70 //

He  attains peace into whom all desires enter as the waters enter the ocean, which  is full to the brim and grounded in stillness, but not the man who is the  desirer of desires.

Just   as the ocean is not at all affected by the  waters  flowing  into  it from all sides an enlightened person , who rests in  his  essential nature or Self is not in the least disturbed by desires produced   by  the objects of enjoyment which he happens  to  come  across during  his  sojourn on earth. Such an individual who maintains  true peace in spite of being a target for the stimuli conveyed through his  sense organs by innumerable sense objects is called a man of perfection, a true  saint. A man attains such a state through constant awareness of the  unchangeable Reality that constitutes his innermost Self. He who looks outside  for enjoyments never attains peace. The principle behind this phenomenon is  that the insentient cannot satisfy the sentient; the sentient can be satisfied  by the sentient alone.

vihaaya  kaamaan yah sarvaan pumaamshcharati nihsprihah
    nirmamo  nirahankaarah sa shaantim adhigacchati // 2.71 //

That man  attains peace who, abandoning all desires, moves about without longing, devoid  of the sense of `I'-ness and `my'-ness.

This  verse explains the mental condition of such a one who finds peace in himself. Such  a sage renounces all desires and is without any longings or attachments. Affinity  for the world exists only because of desires. If desires are given up, no  affinity for the world remains. Such a person’s intellect is without any sense of  `I'-ness or `my'-ness i.e. without any ego which is the cause for the sense of  attachment.

All  the sufferings in the world are caused by our egocentric misconception and consequent  eruption of endless wants.   He is a  genuine Sanyasin who leads a life of constant inspiration gained through  an intelligent renunciation of his egocentric misconceptions.

The  well-known Upanishadic saying is “The human mind is of two kinds, pure and  impure. That which is intent on securing the desires is impure; that which is  free from attachment to desires is pure”.

This  verse answers Arjuna’s question ‘how a man of steadfast mind walks or what is  his mode of conduct?

ULTIMATE STATE OF A PERSON OF STEADY  WISDOM

eshaa  braahmee sthitih paartha nainaam praapya vimuhyati
    sthitwaasyaamantakaale'pi  brahmanirvaanamricchati // 2.72 //

This  is the Brahmi-state, O Son of Pritha. Attaining this, none is deluded.  Being established therein, even at the hour of  death, one attains final liberation in Brahman.

Where  ego ends and the individuality is completely wiped out, a state of Selfhood, the  state of Brahman - Existence, Knowledge, Bliss Absolute - Sat Chit Ananda - dawns.  Renouncing every thing and living in the Self is the Brahmi state or the state  of God-realized soul. If the aspirant attains this state he never falls into delusion  again; never again deluded by the world.  It is the highest state of  happiness. This experience needs to take place at an early age. But if it is  attained even at the time of death he attains liberation. Hence what doubt can  there be about liberation of a man who practices the discipline of renunciation  from an early age and dwells on Brahman throughout life?

“Wisdom  is the supreme means of liberation, but this wisdom is not exclusive of  devotion to God and desireless work. Even while alive, the sage rests in Brahman  and is released from the unrest of the world. The sage of steady wisdom lives a  life of disinterested service. The descriptions of the ideal man, the jnani, the sthitaprajna, the yogarudha, the gunatita or the bhakta agree in all essentials. (Ref. 6.4-32; 10.9-10; 12.13-20; 13.7-11; 14.21-35;  16.1-3; 18.50-60)”. - Dr. S.Radhakrishnan.

Working  without attachment and desires, egoism and vanity, always equanimous with pairs  of opposites is to control the ego and experience the Self. This technique of Karma  Yoga is not different from the technique of meditation or knowledge or devotion.  Such a sage of steady wisdom lives a life of disinterested action. But Arjuna remains  confused and so The Lord explains Karma Yoga further in the next chapter. 

om  tat sat
    iti  srimad bhagavadgeetaasu upanishatsu brahma vidyaayaam yogashaastre
    sri  krishnaarjuna samvaade saankhya yogo naama dvitiyo'dhyaayah

Thus  in the Upanishads of the glorious Bhagavad Gita, the science of  the  Eternal, the scripture of Yoga, the dialogue between  Sri Krishna and  Arjuna ends the second discourse entitled The Yoga of Knowledge.