, yellow. But there is after all nothing in
all this except origination and decease, not of the thing itself, but
of its qualities. The change from green to yellow is the decease of
green colour, the origination of yellow colour. Origination is the
passage of not-being into Being. Decease is the passage of Being into
not-being. Becoming, then, has in it only the two factors of Being and
not-being, and it means the passing of one into the other. But this
passage does not mean, for Heracleitus, that at one moment there is
Being, and at the next moment not-being. It means that Being and
not-being are in everything at one and the same time. Being is {76}
not-being. Being has not-being in it. Take as an example the problem
of life and death. Ordinarily we think that death is due to external
causes, such as accident or disease. We consider that while life
lasts, it is what it is, and remains what it is, namely life, unmixed
with death, and that it goes on being life until something comes from
outside, as it were, in the shape of external causes, and puts an end
to it. You may have read Metchnikoff's book "The Nature of Man." In
the course of that book he develops this idea. Death, he says, is
always due to external causes. Therefore, if we could remove the
causes, we could conquer death. The causes of death are mostly disease
and accident, for even old age is disease. There is no reason why
science should not advance so far as to eliminate disease and accident
from life. In that case life might be made immortal, or at any rate,
indefinitely prolonged. Now this is founded upon a confusion of ideas.
No doubt death is always due to external causes. Every event in the
world is determined, and wholly determined, by causes. The law of
causation admits of no exception whatever. Therefore it is perfectly
true that in every case of death causes precede it. But, as I
explained in the last chapter, [Footnote 6] to give the cause is not
to give any reason for an event. Causation is never a principle of
explanation of anything. It tells us that the phenomenon A is
invariably and unconditionally followed by the phenomenon B, and we
call A the cause of B. But this only means that whenever B happens, it
happens in a certain regular order and succession of events. But it
does not tell us why B happens at all. The reason of a thing is to be
{77} distinguished from its cause. The reason why a man dies is not to
be found in the causes which bring