2. The Full Universe of Leibniz.
The diffusion of
the idea of a Chain of Being in
eighteenth-century
thought was certainly and decisively aided by the
success of Leibniz, a great advocate of the principle
of plenitude and
continuity, which he posited as a
correlative of the principle of
sufficient reason. Leib-
niz, in one of his
letters to Samuel Clarke (1715-16),
writes:
The least corpuscle is actually subdivided infinitely, and
contains
a world of other creatures, of which the universe
would be
deprived, if that corpuscle were an atom, that
is, a body of one
entire piece without subdivision. In like
manner, to say that there
is a vacuum in nature would be
to attribute to God a most imperfect production; it
would
be to violate the great principle of the necessity of a suffi-
cient reason...
(Leibniz Selections, p. 236).
And elsewhere (De synthesi et analysi universali)
the
principle of sufficient reason, whence flows, among
other things,
the fullness of the universe, is defined as
one of the greatest and most
fertile truths of human
cognition, since it assures us that all truths,
even the
most contingent, have an a priori proof,
i.e., a reason
for which they are rather than are not. This bond had
already been established by Leibniz in the Elementa
philosophiae arcanae (1676): the principle of the har-
mony of things requires that there exist the
greatest
possible quantity of essence. There is no gap among
forms; it
is not possible to find an empty space or time.
Every particle of matter
contains infinite creatures (cf.
also the so-called First Truths, Primae veritates [1686]).
The argument is drawn out at length in two other
writings of Leibniz:
De rerum originatione radicali
(1697) and
the Principes de la nature et de la
grâce
(1718, posthumous). “Not only in no one
of the singular
things”—writes Leibniz in the first
of these, “but nei-
ther in the whole
aggregate and series of things, can
one find a sufficient reason for their
existence (nam
non tantum in nullo singulorum, sed nec
in toto aggre-
gato serieque rerum
inveniri potest sufficiens ratio ex-
istendi). The world's reasons must therefore be sought
in something extra-worldly, different from the succes-
sion of states, or series of things, the aggregate of
which
constitutes the world (rationes igitur mundi in
aliquo
extra-mundano, differente a catena statuum, seu serie
rerum, quarum aggregatum mundum constituit).” We
must go back, then, from the physical necessity of
things to their
metaphysical necessity—which would
be precisely their sufficient
reason. Leibniz goes on:
In possible things, or in their very possibility or essence,
there is an
exigency to exist, or (so to speak) claim to exist;
in a word,...
essence of itself tends towards existence.
Whence it follows that all
possible things... tend with
equal right towards existence in
proportion to their quantity
of essence or reality, or according to the
grade of perfection
they contain; for perfection is nothing but the
quantity of
essence.
Thus, given only that there is a reason for the passage
from possibility to
actuality, it will follow that a maxi-
mum of
reality will be actualized. In other words every
possibility has an
“impulsion (conatus) to be real”;
and
the sole restriction in the passage from the possible
to the
actual is that imposed by the criterion of “com-
possibility,” the
reciprocal compatibility of possi-
bilities. From the conflict of all the possibilities which
severally
seek existence, the result will be the existence
of the maximal series of
all possibilities.
The argument is taken up again in the Principes,
in
relation to the problem of the monads. All is full
in nature; every monad
is a living mirror that reflects
the universe; and there is an infinity of
degrees in
monads, les unes dominant plus ou moins sur
les autres
(ibid., pp. 3-4). The sufficient reason for the
existence
of the universe cannot reside in the series of contingent
things, but only in God, from whose perfection it
follows that from the
impulse towards existence proper
to all essences, the most perfect of
possible worlds will
result. Without that we should be unable to say
why
things are, and why they are as they are (ibid., pp.
7-10).
