The Bhagavad Gita (Song of the Lord) is a Vaisnava treatise composed around the time of Christ, or perhaps a century or so before, and incorporated into the text of the epic poem Mahabharata. Its format is that of a series of dialogues between the god Krishna, and the hero Arjuna. It taught that a devotee could manifest a God if he/she did constant japa (chanting a mantra).
Although his cause is just, Arjuna is reluctant to enter into battle against his relatives and teachers, and asks Krishna whether it would not be preferable to simply abandon the fight. Krishna's answer takes the form of a lengthy (seventeen out of a total eighteen chapters) discourse. His answer is that Arjuna (being a kshatriya, or member of the warrior class) has a duty to fight, but should remain unattached to the "fruits" of his action, devoting these to Krishna. In the process, several "yogas" are distinguished:
- Karmayoga (the yoga of "action" in the world)
- Jnanayoga (the yoga of study and the pursuit of wisdom)
- Bhaktiyoga (the yoga of religious devotion)
Other yogas are sometimes identified in the Gita as well.
The question of which yoga the Gita intends to recommend is a major question occupying Hindu philosophers. Sankara is the most prominent philosophical exponent of jnanayoga; Ramanuja, of bhaktiyoga; and M.K. Gandhi, of karmayoga. A number of commentators see the three as harmonious; an example would be the "integral yoga" (purnayoga) of Sri Aurobindo.