is obscure, but the reply is more definite.  The Self is indestructible but still it is incorrect to speak of the soul having knowledge and perception after death, for knowledge and perception imply duality, a subject and an object.  But when the human soul and the universal Atman are one, there is no duality and no human expression can be correctly used about the Atman.  Whatever you say of it, the answer must be neti, neti, it is not like that[184]; that is to say, the ordinary language used about the individual soul is not applicable to the Atman or to the human soul when regarded as identical with it.

This identity is stated more precisely in another passage[185] where first occurs the celebrated formula Tat tvam asi, That art Thou, or Thou art It[186], i.e. the human soul is the Atman and hence there is no real distinction between souls.  Like Yajniavalkya’s teaching, the statement of this doctrine takes the form of an intimate conversation, this time between a Brahman, Uddalaka Aruni, and his son Svetaketu who is twenty-four years of age and having just finished his studentship is very well satisfied with himself.  His father remarks on his conceit and says “Have you ever asked your teachers for that instruction by which the unheard becomes heard, the unperceived perceived and the unknown known?” Svetaketu enquires what this instruction is and his father replies, “As by one lump of clay all that is made of clay is known, and the change[187] is a mere matter of words, nothing but a name, the truth being that all is clay, and as by one piece of copper or by one pair of nail-scissors all that is made of copper or iron can be known, so is that instruction.”  That is to say, it would seem, the reality is One:  all diversity and multiplicity is secondary and superficial, merely a matter of words.  “In the beginning,” continues the father, “there was only that which is, one without a second.  Others say in the beginning there was that only which is not (non-existence), one without a second, and from that which is not, that which is was born.  But how could that which is be born of that which is not[188]?  No, only that which is was in the beginning, one only without a second.  It thought, may I be many:  may I have offspring.  It sent forth fire.”  Here follows a cosmogony and an explanation of the constitution of animate beings, and then the father continues—­“All creatures have their root in the Real, dwell in the Real and rest in the Real.  That subtle being by which this universe subsists, it is the Real, it is the Atman, and thou, Svetaketu, art It.”  Many illustrations of the relations of the Atman and the universe follow.  For instance, if the life (sap) leaves a tree, it withers and dies.  So “this body withers and dies when the life has left it:  the life dies not.”  In the fruit of the Banyan (fig-tree) are minute seeds innumerable.  But the imperceptible subtle essence in each seed is the whole Banyan.  Each example