those we know. With another chemical substratum, in other physical
conditions, the impulsion would have remained the same, but it would
have split up very differently in course of progress; and the whole
would have traveled another road--whether shorter or longer who can
tell? In any case, in the entire series of living beings no term would
have been what it now is. Now, was it necessary that there should be a
series, or terms? Why should not the unique impetus have been impressed
on a unique body, which might have gone on evolving?

This question arises, no doubt, from the comparison of life to an
impetus. And it must be compared to an impetus, because no image
borrowed from the physical world can give more nearly the idea of it.
But it is only an image. In reality, life is of the psychological order,
and it is of the essence of the psychical to enfold a confused plurality
of interpenetrating terms. In space, and in space only, is distinct
multiplicity possible: a point is absolutely external to another point.
But pure and empty unity, also, is met with only in space; it is that of
a mathematical point. Abstract unity and abstract multiplicity are
determinations of space or categories of the understanding, whichever we
will, spatiality and intellectuality being molded on each other. But
what is of psychical nature cannot entirely correspond with space, nor
enter perfectly into the categories of the understanding. Is my own
person, at a given moment, one or manifold? If I declare it one, inner
voices arise and protest--those of the sensations, feelings, ideas,
among which my individuality is distributed. But, if I make it
distinctly manifold, my consciousness rebels quite as strongly; it
affirms that my sensations, my feelings, my thoughts are abstractions
which I effect on myself, and that each of my states implies all the
others. I am then (we must adopt the language of the understanding,
since only the understanding has a language) a unity that is multiple
and a multiplicity that is one;[91] but unity and multiplicity are only
views of my personality taken by an understanding that directs its
categories at me; I enter neither into one nor into the other nor into
both at once, although both, united, may give a fair imitation of the
mutual interpenetration and continuity that I find at the base of my own
self. Such is my inner life, and such also is life in general. While, in
its contact with matter, life is comparabl