Summary:
The Bhagavad Gita is one of the most influential books in history I would argue. And for that reason alone it's worth reading, to get a broader idea of different cultures and see where ideas come from and how old some of them are. It is connected in thought with lots of other philosophical directions, like Taoism or Stoicism.
But besides that, it's a text of deep belief and a window into the religion of Hinduism. But hidden in it are absolute gems of wisdom, eternal, never changing capital "T" Truths about the world, that are rediscovered time and time again by thinkers around the world. I think it's impossible to summarize the main ideas because every other sentence is full of wisdom, but some of the key concepts keep occurring, over and over again:
Attachment is bad. Freedom is breaking free from attachments. Caring about the future and how it is going to unfold is futile, is attachment. However you should still do your best, not for the sake of attaining a better future, but because it's the only way. The self is there to be overcome, desires and pains are hindrances on the path to freedom. Wisdom and Enlightenment is when somebody has truly internalized these ideas. When their self is no longer attached, their ego has subsided, when they are no longer attached to the world, but free from it. Then they are like god. Eternal.
This same idea is the core idea of Buddhism as well. In a way, Buddhism is the raw philosophy of Hinduism, stripped of the gods.
One of my favorite quotes is from this book, I will include it here in the summary:
The self is a friend for him who masters himself by the Self; but for him who is not self-mastered, the self is the cruelest foe.
To me, struggling with an addictive and very much worldly attached self, this quote stings, every time I read it because it hits home.
Notes:
Introduction
Bhagavad Gita means "The Song of the Blessed One".
The backdrop is a dialogue between two armies fighting, where the leader of one side stops in the middle of the battle to discourse with his companion - Krishna - a god about the meaning of it all.
Not only is there nothing to overcome, there is no one in particular to overcome it.
High spiritual warfare is one of the ego's self-aggrandizing dreams. After a while, all this struggle drops away naturally.
We are the goal; we are always peace.
The primary question is: How should we live?
The essence of Hinduism is "Let go".
The Gita is a love song to reality, a hymn in praise of everything excellent and beautiful and brave.
I am death, shattered of worlds, annihilating all things.
Realizing that both the creative and the destructive issue from the infinite intelligence of the universe allows us to accept the whole of reality.
Indifferent to scriptures, your mind stands by itself, unmoving, absorbed in deep meditation. This is the essence of yoga.
The healthiest way to begin reading and absorbing a text like the Bhagavad Gita is to understand that ultimately it has nothing to teach.
About the Translation
A man whose nature is dominated by sattva will be clear- thinking, radiant and truthful. A man whose nature is dominated by rajas will be passionate, quick to anger and greedy. A man whose nature is dominated by tamas will be stupid, lazy and stubborn. But most men will be found to have elements of gunas different from their dominating ones.
The aim of the upward-reaching atman, or Self, is to transcend the gunas, break free of their bondage, and attain liberation.
This sounds very much like the ideas of Buddhism. Probably because Buddhism has taken a lot of inspiration from Hinduism back when it was created.
Chapter 1 - Arjuna's Despair
What good is kingship, of happiness, of life itself when those for whose sake we desire them - teachers, fathers, sons, grandfathers, uncles, fathers-in-law, grandsons, brothers-in-law, and other kinsmen - stand here in battle ranks, ready to give up their fortunes and their lives?
Chapter 2 - The Practice of Yoga
If I killed them, all my earthly pleasures would be smeared with blood.
Physical sensations - cold and heat, pleasure and pain - are transient: they come and go; so bear them patiently Arjuna.
Non-being can never be; being can never not be.
The wise man lets go of all results, whether good or bad, and is focused on the action alone. Yoga is skill in actions.
If a man keeps dwelling on sense-objects, attachment to them arises; from attachment, desire flares up; from desire, anger is born; from anger, confusion follows; from confusion, weakness of memory; weak memory - weak understanding; weak understanding - ruin.
Attaching to the outcomes of things and trying to influence them for the sake of the outcome only, will usually make things worse. The better way is to do your best, no matter what. That's the idea of the Tao Te Ching as well as the idea of Stoics such as Markus Aurelius as well as that of more modern psychology/philosophy books like Grit by Angela Duckworth
Chapter 3 - The Yoga of Action
Beings arise from food; food arises from rain; rain arises from worship; worship, from ritual action; ritual action, from God; God, from the deathless Self. Thus, the all-present God requires the worship of men.
Whatever a great man does ordinary people will do; whatever standard he sets everyone else will follow.
If I stopped acting, these worlds would plunge into ruin; chaos would overpower all beings; mankind would be destroyed.
The above is the main idea of Atlas Shrugged in disguise. If people stopped acting, they would soon perish. So, even when we have to act, we act, without caring about the fact that we are acting and about what we accomplish.
Desire dwells in the senses, the mind, and the understanding; in all these it obscures wisdom and perplexes the embodied Self.
Chapter 4 - The Yoga of Wisdom
With no desire for success, no anxiety about failure, indifferent to results, he burns up his actions in the fire of wisdom.
There is nothing that he expects, nothing that he fears. Serene, free from possessions, untainted, acting with the body alone.
Wisdom is the final goal of every action.
Chapter 5 - The Yoga of Renunciation
A man unattached to sensations, who finds fulfilment in the Self, whose mind has become pure freedom, attains an imperishable joy.
When desire, fear, and anger have left him, that man is forever free.
Chapter 6 - The Yoga of Meditation
The self is a friend for him who masters himself by the Self; but for him who is not self-mastered, the self is the cruelest foe.
Constantly mastering his mind, the man of yoga grows peaceful, attains supreme liberation, and vanishes into bliss.
Abandoning all desires born of his own selfish will, a man should learn to restrain his unruly senses with his mind.
Chapter 7 - Wisdom and Realization
Men whose wisdom is darkened by desires, men who are hemmed in by the limits of their natures, take refuge in other gods.
Chapter 8 - Absolute Freedom
Freedom is union with the deathless; the Self is the essence of all things; its creative power, called action, causes the whole world to be.
Chapter 9 - The Secret of Life
Chapter 10 - Divine Manifestations
Chapter 11 - The Cosmic Vision
Chapter 12 - The Yoga of Devotion
Knowledge is better than practice; meditation is better than knowledge; and best of all is surrender, which soon brings peace.
Chapter 13 - The Field and Its Knower
He who sees that all actions are performed by Nature alone and thus that the self is not the doer - that man sees truly.
Chapter 14 - The Three Gunas
Chapter 15 - The Ultimate Person
Serene, with desires extinguished, released from pleasure and pain, from joy and suffering, the wise attain that eternal state.
Chapter 16 - Divine Traits and Demonic Traits
Fearlessness, purity of heart, persistence in the yoga of knowledge, generosity, self-control, nonviolence, gentleness, candor, integrity, disengagement, compassion for all beings, modesty, patience, a tranquil mind, dignity, kindness, courage, a benevolent, loving heart - these are the qualities of men born with divine traits.
Chapter 17 - Three Kinds of Faith
Chapter 18 - Freedom through Renunciation
To give up desire-bound actions is what is meant by renouncing; to give up the results of all actions is what the wise call to relinquish.
An embodied being can never relinquish actions completely; to relinquish the results of actions is all that can be required.
Understanding is tamasic when, thickly covered in darkness, it imagines that wrong is right and sees the world upside down.
Rajasic happiness comes from contact between the senses and their objects, and is at first like nectar, but at last like poison.
With a purified understanding, fully mastering himself, relinquishing all sense-objects, released from aversion and craving, solitary, eating lightly, controlling speech, mind, and body, absorbed in deep meditation at all times, calm, impartial, free from the "I" and "mine", from aggression, arrogance, greed, desire, and anger, he is fit for the state of absolute freedom.
The thing that, in your delusion, you wish not to do, you will do, even against your will, since your karma binds you.
Appendix
Man is not at peace with himself till he has become like God. - Gandhi
He is a true devotee who is jealous of no one, who is a fount of mercy, who is without egotism, who is selfless, who treats alike cold and heat, happiness and misery, who is always forgiving, who is always contented, whose resolutions are firm, who has dedicated mind and soul to God, who causes no dread, who is not afraid of others, who is free from exultation sorrow, and fear, who is pure, who is versed in action and yet remains unaffected by it, who renounces all fruits of action, good or bad, who treats friends and enemy alike, who is untouched by respect or disrespect, who is not puffed up by praise, who does not go under when people speak ill of him, who loves silence and solitude, who has a disciplined mind. Such devotion is inconsistent with the existence at the same time of strong attachments.
He who is always brooding over results often loses nerve in the performance of his duty. He becomes impatient and then gives vent to anger and begins to do unworthy things; he jumps from action to action, never remaining faithful to any. He who broods over results is like a man given to objects of the senses: he is always distracted he says good-bye to all scruples, everything is right in his estimation, and he therefore resorts to means fair and foul to attain his end.
All acts that are incapable of being performed without attachment are taboo.
Desire for fruit is the only universal prohibition. Desirelessness is obligatory.