ore complicated, and also more and more differentiated, are born of the
association of organisms barely differentiated and elementary.[93] In
this extreme form, the theory is open to grave objections: more and
more the idea seems to be gaining ground, that polyzoism is an
exceptional and abnormal fact.[94] But it is none the less true that
things happen _as if_ every higher organism was born of an association
of cells that have subdivided the work between them. Very probably it is
not the cells that have made the individual by means of association; it
is rather the individual that has made the cells by means of
dissociation.[95] But this itself reveals to us, in the genesis of the
individual, a haunting of the social form, as if the individual could
develop only on the condition that its substance should be split up into
elements having themselves an appearance of individuality and united
among themselves by an appearance of sociality. There are numerous cases
in which nature seems to hesitate between the two forms, and to ask
herself if she shall make a society or an individual. The slightest push
is enough, then, to make the balance weigh on one side or the other. If
we take an infusorian sufficiently large, such as the Stentor, and cut
it into two halves each containing a part of the nucleus, each of the
two halves will generate an independent Stentor; but if we divide it
incompletely, so that a protoplasmic communication is left between the
two halves, we shall see them execute, each from its side, corresponding
movements: so that in this case it is enough that a thread should be
maintained or cut in order that life should affect the social or the
individual form. Thus, in rudimentary organisms consisting of a single
cell, we already find that the apparent individuality of the whole is
the composition of an _undefined_ number of potential individualities
potentially associated. But, from top to bottom of the series of living
beings, the same law is manifested. And it is this that we express when
we say that unity and multiplicity are categories of inert matter, that
the vital impetus is neither pure unity nor pure multiplicity, and that
if the matter to which it communicates itself compels it to choose one
of the two, its choice will never be definitive: it will leap from one
to the other indefinitely. The evolution of life in the double direction
of individuality and association has therefore nothing accidental about