Sanjaya explains the condition of Arjuna, who is agitated by attachment and fear. Krishna rebukes Arjuna for his dejection and exhorts him to fight.
When conflicting thoughts arise in the mind, few people know what to do. At this stage the advice of a teacher is needed. When the ego receives repeated blows from the world, it realizes its helplessness. It wants to have peace and turns to the Supreme Power.
After failing to convince Krishna through his seemingly wise thoughts, Arjuna realizes his helplessness and becomes Krishna's disciple in the true sense. Only now can Krishna take on the role of the teacher.
Krishna, smilingly, proceeds to enlighten Arjuna by various means. He first explains the imperishable nature of the Atman, for which there is no past, present and future. The Atman never dies, therefore Arjuna should not grieve. As it transcends the five elements, viz., earth, water, fire, air and ether, it cannot be cut, wetted, burnt, or dried. It is eternal and unchanging. Without desire for the result, the mind is calm during action. The one-pointedness of the wise is due to the absence of desires; the scattered nature of the intellect of the ignorant is due to desires. With a one-pointed intellect alone can one hope to reach the immortal. Krishna praises the unselfish worker (karma yogi) possessed of equanimity of mind and asks Arjuna to be the same even in battle. He advises Arjuna to fight, free from desire for acquisition of kingdom or preservation of it. By this method one can go beyond the qualities (gunas) of nature - sattva, rajas and tamas - and be established in the Atman. Those who know the Atman understand that there is nothing worth possessing in the three worlds. For this, one should have balance of mind in success and failure, pleasure and pain - skill in action is called yoga.
On hearing this, Arjuna raises four questions about the characteristics of a person of stable mind, i.e., his description, how he speaks, sits and walks. Krishna says that a stable-minded person will have no desires at all. The consciousness of the Atman and abandonment of desires are simultaneous experiences. A person established in wisdom will take things as they come and will not have any likes and dislikes. His senses will be withdrawn like the tortoise withdrawing its limbs. Being conscious of the presence of God in all, one can control the senses. Krishna compares the uncontrolled mind to a boat caught up in a storm. Due to the wind of desires blowing over the mind, it is tossed about and induced to do wrong actions. The dark night of an ordinary person is the condition of wakefulness to the self-controlled one, and vice versa. All the particularities merge in the universal Selfhood of a stable-minded sage. The sage of steady wisdom lives a life of disinterested service.
Chapter 2 teaches the applicability of yoga in daily life. Krishna gives a comprehensive understanding of how human sufferings could be relieved with the awareness of the Absolute. He shows humanity the way to overcome duality and conflicts. He asks us to be a witness, be free from the three gunas, live above duality, act without expectation of result and identify with Supreme Consciousness.
Note: In the Bhagavad Gita the word 'Sankhya' usually refers to jnana yoga, the term 'yog' to karma yoga.