Contrary to popular opinion, the notion of kamma is not a timeless, universal feature of Indian religions. It is a specific doctrine that explains ethical action and its consequences, and appears at a specific time and place. That time was a few generations before the Buddha; the place was the region of Mithila, in between the Sakyan republic and Vesali.
This was when the great Upanishadic sage Vajnavalkya flourished. Among many other crucial innovations in the Brahmanical teachings, he is responsible for the earliest clear statements on kamma. At that time, this teaching was an esoteric doctrine. In later years, of course, this compelling doctrine became firmly established in both Buddhism and Jainism, and due in part to their influence, became known throughout Hinduism.
The following is part of a dialogue in the Brihadarannyaka Upanishad between Vajnavalkya and King Janaka of Mithila, who is also mentioned in the Jatakas. In the opening of this dialogue (at BU 4.3.1; scroll down to ‘third brahmana’), Yajnavalkya shows his reluctance to debate the king, a sign of the esoteric nature of the teachings, as opposed to the many other public debates in this text.
1. Yagnavalkya continued: ‘Now when that Self, having sunk into weakness, sinks, as it were, into unconsciousness, then gather those senses (pranas) around him, and he, taking with him those elements of light, descends into the heart. When that person in the eye turns away, then he ceases to know any forms.
2. ‘”He has become one,” they say, ” he does not see.” “He has become one,” they say, “he does not smell.” “He has become one,” they say, “he does not taste.” “He has become one,” they say, “he does not speak.” “He has become one,” they say, “he does not hear.” “He has become one,” they say, “he does not think.” “He has become one,” they say,” he does not touch.” “He has become one,” they say, “he does not know.” The point of his heart becomes lighted up, and by that light the Self departs, either through the eye, or through the skull, or through other places of the body. And when he thus departs, life (the chief prana) departs after him, and when life thus departs, all the other vital spirits (pranas) depart after it. He is conscious, and being conscious he follows and departs.
‘Then both his knowledge and his kamma take hold of him, and his acquaintance with former things.’
3. ‘And as a caterpillar, after having reached the end of a blade of grass, and after having made another approach (to another blade), draws itself together towards it, thus does this Self, after having thrown off this body and dispelled all ignorance, and after making another approach (to another body), draw himself together towards it.
4. ‘And as a goldsmith, taking a piece of gold, turns it into another, newer and more beautiful shape, so does this Self, after having thrown off this body and dispelled all ignorance, make unto himself another, newer and more beautiful shape, whether it be like the Fathers, or like the Gandharvas, or like the Devas, or like Pragapati, or like Brahman, or like other beings.
5. ‘That Self is indeed Brahman, consisting of knowledge, mind, life, sight, hearing, earth, water, wind, ether, light and no light, desire and no desire, anger and no anger, right or wrong, and all things. Now as a man is like this or like that, according as his kamma and according as he behaves, so will he be: a man of good kammas will become good, a man of bad kammas, bad. He becomes pure by pure kammas, bad by bad kammas.
‘And here they say that a person consists of desires. And as is his desire, so is his will; and as is his will, so is his kamma; and whatever kamma he does, that he will reap.
6. ‘And here there is this verse: “To whatever object a man’s own mind is attached, to that he goes strenuously together with his kamma; and having obtained the end (the last results) of whatever kamma he does here on earth, he returns again from that world (which is the temporary reward of his deed) to this world of kamma.”
‘So much for the man who desires. But as to the man who does not desire, who, not desiring, freed from desires, is satisfied in his desires, or desires the Self only, his vital spirits do not depart elsewhere,- being Brahman, he goes to Brahman.
7. ‘On this there is this verse:
“When all desires which once entered his heart are undone,
then does the mortal become immortal,
then he obtains Brahman.
“And as the slough of a snake lies on an ant-hill,
dead and cast away, thus lies this body;
but that disembodied immortal spirit (prana = life)
is Brahman only, is only light.”