Chapter 2 - Sankhya Yoga

Sankhya yoga is said to be the most important chapter of the Gita. This is in essence the summary the whole Gita and gives an idea of what is to be elaborated in the subsequent chapters. some of the most popular verses of the Gita are drawn from this chapter. 

Summary 

Sankhya means number and deals with duality - Purusha and Prakriti - the indestructible and the destructible aspects of creation. It also touches upon the purity of the inner faculties or Antahkarana - involving mind, intellect and memory - thereby defining right action, right judgement, right remembrance and stability of the inner faculties. It also emphasises on the strength one gains by not yielding to the cravings of the senses and how the wise can withdraw from the senses (world or prakriti) and establish in the Self (Purusha). Krishna touches upon Karma yoga, Gnana yoga, Kriya yoga and describes the qualities of a Yogi (Stitha Pragna - one who is established in the awareness of the Self).

Yathartha

Gnana Yoga

Only the body perishes, the soul continues. So there is no need to feel sad when the soul leaves the body (physical death). Soul stays invisible before birth and after death, but doesn’t disappear. It continues to exist. It has no name or form and its only the body which has a name and form that perishes. Destroying the body you don’t destroy anything that would anyway not be destroyed. Very few wise realise this true nature of life.

Karma Yoga
only a few privileged get an opportunity to establish Dharma. it has come knocking at your door. If you give up now, you will be called a sinner and a coward. if you win this war - you rule the world and if you lose you attain Heaven. so you have nothing to lose. Give your 100% and fight without feverishness.
Know that you are only responsible for your intentions and actions and not the results the actions - Karmanyava Adhikaraste Ma Phaleshu Kadachana.  Act with equanimity - Yogastu Kuru Karmaani - without being deluded by the mind.  Be steadfast and act free from the storm of emotions. When you are freed from delusion through my wisdom, dispassion arises. Understand the true nature of the world and the Self, and act skillfully - Yogastu Karmani Kaushalam

who is a Sthitah Pragna?

• one who is established in the awareness of the Self
• not depressed by sorrow nor elated by joy
• free from craving, fear and anger
• not swayed by prosperity or loss

Thought of pleasure brings desire for pleasure and obstacles in the path of desire brings anger. Anger clouds the intellect and actions of poor judgement bring about a man’s downfall. As one gets older, the senses get weaker and are no longer able to enjoy the pleasures, but the craving for pleasure never gets weak. These cravings can make even a strong person’s mind weak. sthitha pragna is one in whom the cravings have perished, senses are steady and so is the mind. He is able to withdraw from the sensory pleasures like the tortoise withdraws into its shell.

Purity in the inner faculties - Mind, Intellect and Memory - is attained by having a say over the senses. This purity brings pleasantness in the mind and stability in the intellect. When craving for pleasure, mind is unstable and the inner faculties are tainted. Tainted inner faculties lead to disturbance in mind and when the mind is disturbed, how can one be happy? Just like a tornado can blow away a ship, the craving for pleasure can derail the intellect. Just like the raging rivers flow and settle into the calm sea, the senses settle in a mature intellect of the Stitha Pragna

When the world is asleep, the Sthitha Pragna stays alert seeking the Self and when the world is awake and running behind pleasure, he rests as if in sleep. Established in the knowledge of the Self, he stays unshakeable and even at the time of death remains unfazed, blissful, and attains liberation.