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 (Jîva) 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 Viññâṇa, or consciousness, and the expression paṭisandhiviññâṇam or rebirth-consciousness occurs[431]. The question is treated in an important dialogue in the Majjhima-Nikâya[432], where a monk called Sâti maintains that, according to the Buddha's teaching, consciousness transmigrates unchanged. The Buddha summoned Sâti and rebuked his error in language of unusual severity, for it was evidently capital and fatal if persisted in. The Buddha does not state what transmigrates, as the European reader would wish him to do, and would no doubt have replied to that question that it is improperly framed and does not admit of an answer. His argument is directed not so much against the idea that consciousness in one existence can have some connection with consciousness in the next, as against the idea that this consciousness is a unity and permanent. He maintains that it is a complex process due to many causes, each producing its own effect. Yet the Pitakas seem to admit that the processes which constitute consciousness in one life, can also produce their effect in another life, for the character of future lives may be determined by the wishes which we form in this life. Existence is really a succession of states of consciousness following one another irrespective of bodies. If _ABC_ and _abc_ are two successive lives, _ABC_ is not more of a reality or unity than _BCa_. No personality passes over at death from _ABC_ to _abc_ but then _ABC_ is itself not a unity: it is merely a continuous process of change[433].