It is unfortunate for us that the doctrine of reincarnation met with almost universal assent in India[429].  If some one were to found a new Christian sect, he would probably not be asked to prove the immortality of the soul:  it is assumed as part of the common religious belief.  Similarly, no one asked the Buddha to prove the doctrine of rebirth.  If we permit our fancy to picture an interview between him and someone holding the ordinary ideas of an educated European about the soul, we may imagine that he would have some difficulty in understanding what is the alternative to rebirth.  His interlocutor might reply that there are two types of theory among Europeans.  Some think that the soul comes into existence with the body at birth but continues to exist everlasting and immortal after the death of the body.  Others, commonly called materialists, while agreeing that the soul comes into existence with the birth of the body, hold that it ceases to exist with the death of the body.  To the first theory the Buddha would probably have replied that there is one law without exception, namely that whatever has a beginning has also an end.  The whole universe offers no analogy or parallel to the soul which has a beginning but no end, and not the smallest logical need is shown for believing a doctrine so contrary to the nature of things.  And as for materialism he would probably say that it is a statement of the processes of the world as perceived but no explanation of the mental or even of the physical world.  The materialists forget that objects as known cannot be isolated from the knowing subject.  Sensation implies contact and duality but it is no real explanation to say that mental phenomena are caused by physical phenomena.  The Buddha reckoned among vain speculations not only such problems as the eternity and infinity of the world but also the question, Is the principle of life (Jiva) identical with the body or not identical.  That question, he said, is not properly put, which is tantamount to condemning as inadequate all theories which derive life and thought from purely material antecedents[430].  Other ideas of modern Europe, such as that the body is an instrument on which the soul works, or the expression of the soul, seem to imply, or at least to be compatible with, the pre-existence of the soul.

It is probable too that the Buddha would have said, and a modern Buddhist would certainly say, that the fact of rebirth can easily be proved by testimony and experience, because those who will make the effort can recall their previous births.  For his hearers the difficulty must have been not to explain why they believed in rebirth but to harmonize the belief with the rest of the master’s system, for what is reborn and how?  We detect a tendency to say that it is Vinnana, or consciousness, and the expression patisandhivinnanam or rebirth-consciousness occurs[431].  The question is treated in an important dialogue in the Majjhima-Nikaya[432], where a monk called Sati