The same Upanishad contains an interesting conversation, in which King Ajātaçatru of Kāçi (Benares) instructs the Brahman, Bālāki Gārgya, that Brahma is not the spirit (purusha) which is in sun, moon, wind, and other natural phenomena, or even in the (waking) soul (ātman), but is either the dreaming soul, which is creative, assuming any form at pleasure, or, in the highest stage, the soul in dreamless sleep, for here all phenomena have disappeared. This is the first and the last condition of Brahma, in which no world exists, all material existence being only the phantasms of the dreaming world-soul.
Of somewhat similar purport is a passage of the Chhāndogya (viii. 7–12), where Prajāpati is represented as teaching the nature of the Ātman in three stages. The soul in the body as reflected in a mirror or water is first identified with Brahma, then the dreaming soul, and, lastly, the soul in dreamless sleep.
How generally accepted the pantheistic theory must have become by the time the disputations at the court of King Janaka took place, is indicated by the form in which questions are put. Thus two different sages in the Bṛihadāraṇyaka (iii. 4, 5) successively ask Yājnavalkya in the same words: “Explain to us the Brahma which is manifest and not hidden, the Ātman that dwells in everything.”
With the doctrine that true knowledge led to supreme bliss by the absorption of the individual soul in Brahma went hand in hand the theory of transmigration (saṃsāra). That theory is developed in the oldest Upanishads; it must have been firmly established by the time Buddhism arose, for Buddha accepted it without question. Its earliest form is found in the Çatapatha Brāhmaṇa, where the notion of being born again after death and dying repeatedly is coupled with that of retribution. Thus it is here said that those who have correct knowledge and perform a certain sacrifice are born again after death for immortality, while those who have not such knowledge and do not perform this sacrifice are reborn again and again, becoming the prey of Death. The notion here expressed does not go beyond repeated births and deaths in the next world. It is transformed to the doctrine of transmigration in the Upanishads by supposing rebirth to take place in this world. In the Bṛihadāraṇyaka we further meet with the beginnings of the doctrine of karma, or “action,” which regulates the new birth, and makes it depend on a man’s own deeds. When the body returns to the elements, nothing of the individuality is here said to remain but the karma, according to which a man becomes good or bad. This is, perhaps, the germ of the Buddhistic doctrine, which, though denying the existence of soul altogether, allows karma to continue after death and to determine the next birth.
The most important and detailed account of the theory of transmigration which we possess from Vedic times is supplied by the Chhāndogya Upanishad. The forest ascetic possessed of knowledge and faith, it is here said, after death enters the devayāna, the “path of the gods,” which leads to absorption in Brahma, while the householder who has performed sacrifice and good works goes by the pitṛiyāṇa or “path of the Fathers” to the moon, where he remains till the consequences of his actions are exhausted. He then returns to earth, being first born again as a plant and afterwards as a man of one of the three highest castes. Here we have a double retribution, first in the next world, then by transmigration in this. The former is a survival of the old Vedic belief about the future life. The wicked are born again as outcasts (chaṇḍālas), dogs or swine.
The account of the Bṛihadāraṇyaka (VI. ii. 15–16) is similar. Those who have true knowledge and faith pass through the world of the gods and the sun to the world of Brahma, whence there is no return. Those who practise sacrifice and good works pass through the world of the Fathers to the moon, whence they return to earth, being born again as men. Others become birds, beasts, and reptiles.
The view of the Kaushītaki Upanishad (i. 2–3) is somewhat different. Here all who die go to the moon, whence some go by the “path of the Fathers” to Brahma, while others return to various forms of earthly existence, ranging from man to worm, according to the quality of their works and the degree of their knowledge.
The Kāṭhaka, one of the most remarkable and beautiful of the Upanishads, treats the question of life after death in the form of a legend. Nachiketas, a young Brahman, visits the realm of Yama, who offers him the choice of three boons. For the third he chooses the answer to the question, whether man exists after death or no. Death replies: “Even the gods have doubted about this; it is a subtle point; choose another boon.” After vain efforts to evade the question by offering Nachiketas earthly power and riches, Yama at last yields to his persistence and reveals the secret. Life and death, he explains, are only different phases of development. True knowledge, which consists in recognising the identity of the individual soul with the world soul, raises its possessor beyond the reach of death:—
When every passion vanishes
That nestles in the human heart,