The tradition of recorded philosophical thought of the Indian subcontinent is as ancient, rich and subtle as any in the world. With roots in the insights of rishis, or seers, in the second millennium BCE, the tradition has developed continuously since that time, diversifying into the many schools of Hindu thought, together with Buddhism, Sikhism and Jainism. The thinkers in this tradition investigate all the great philosophical questions: in all the branches of philosophy, the great options have been explored with rigor and thoroughness, and this central philosophical business goes on to this day.
The first evidence of philosophical thought occurs in the great collections of hymns we know as the Vedas. As Radhakrishnan puts it, in the Rig Veda one finds generally ‘the earliest phase of religious consciousness where we have not so much the commandments of priests as the outpourings of poetic minds who were struck by the immensity of the universe and the inexhaustible mystery of life’. Most of the hymns are addressed to individual deities, but there are places in which a polytheistic account of reality is found wanting, and there is an intuition that there must be a single first principle behind all phenomena. Thus, in the important ‘Creation Hymn’ (S: Nasadiya) it is stated that ‘The gods came afterwards, with the creation of this universe’. Before the gods and this universe:
There was neither death nor immortality then. There was no distinguishing sign of night or of day. That one [S: tad ekam] breathed, windless, by its own impulse. Other than that there was nothing beyond. Prior to the universe there was tad ekam, something self-sufficient, to which no distinctions apply.
Hints such as these are taken up and developed philosophically in the Upanisads, constituting collectively one of the world’s greatest and most seminal philosophical works. The thought of the Upanisads stands to Indian thought much as does that of Plato and Aristotle to the West or that of Lao Tzu and Confucius to China: their leading ideas set the philosophical agenda for their tradition, and they have remained a living source of inexhaustible significance ever since they were composed. Though the work of many hands and many years, the Upanisads set out a coherent philosophical outlook. The world of ordinary human experience, of individuals standing in mutual causal relations in space and time (in S the samsara) is not reality. Reality is a oneness or absolute, changeless, perfect and eternal, Brahman. Again, human nature is not exhausted by its samsaric elements of body and individual consciousness or mind (S: jiva): there is further present in each one of us an immortal element, our true self, and the atman. The atman has no form, and whatever is without form is without limit; whatever is without limit is omnipresent, and whatever is omnipresent and immortal is God. This is the basis for one of the most striking and central of Upanisadic doctrines, the assertion that Brahman and atman are in some sense the same:
Containing all works, containing all desires, containing all tastes, encompassing this whole world, without speech, without concern, this is the self [atman] of mine within the heart; this is Brahman. Into him, I shall enter, on departing hence.
It is this doctrine which is summed up in the phrase ‘that art thou’ (S: tat tvam asi), ‘that’ referring to Brahman.
If reality is Brahman, eternal, immutable, perfect, then an account must be given of the origin and status of the ordinary world of change, the samsara. The view given in the Upanisads to explain the