1. Two Objections.
There seems to have been only
two dissident voices in this ideal
climate, namely, those
of Dr. Johnson and Voltaire. Samuel Johnson (in
1757)
applied Zeno's argument to the Chain of Being.
The Scale of Existence from Infinity to Nothing cannot
possibly have
Being. The highest Being not infinite must
be... at an infinite
Distance below Infinity... and in
this Distance, between finite and
infinite, there will be
Room for ever for an infinite series of
indefinable Existence.
Between the lowest positive existence and
Nothing,... is
another chasm infinitely deep; where there is room
again
for endless Orders of subordinate Nature.... Nor is this
all. In the Scale... there are infinite Vacuities. At whatever
Distance we suppose the next Order of Being to be above
Man, there
is room for an intermediate Order of Beings
between them; and if
for one Order, then for infinite Orders;
since every Thing that
admits of more or less, and conse-
quently all the Parts of that which admits them, may be
infinitely divided...
(A Review of a Free Inquiry into the
Nature
and Origin of Evil).
Johnson's argument, as we see, strikes directly at the
foundation of the
Chain of Being—the principle of
plenitude. Still, with a
moment's reflection, we see that
it is not really pertinent: the Chain of
Being is, so to
speak, the cosmological translation of Zeno's paradox,
and its fullness is predicated precisely upon the
“fault”
Johnson finds with it, namely, that infinite
divisibility
which affords the insertion between one order and
another
of “endless orders.”
Voltaire, on the other hand, questions on the basis
of empirical observation
whether it can be held that
there is a gradation of created beings
(Dictionnaire
philosophique [1764], s.v.
“Chaîne des êtres
créés”). It
is gratifying to the imagination,
he says, to contemplate
that imperceptible passage from the inanimate to
the
organic, from plants to zoophytes, to animals, to angels,
all in
ascending grades of perfection up to God Him-
self. This hierarchy pleases the bons gens,
who believe
they recognize in it the Pope, followed by the cardi-
nals, archbishops, and bishops, followed
in turn by the
curates, vicars, and simple priests, deacons and sub-
deacons, lastly by friars and capuchins.
But there is
an essential difference between the cosmological and
ecclesiastical hierarchies: whereas in the latter the
humblest member can
be Pope, in the former not even
the most perfect of creatures can become
God. And
with this apparently jesting observation Voltaire
catches an
essential feature of the Chain of Being—its
immobility: if the
principle of plenitude requires that
every grade be filled by an order of
creatures, this
hierarchy must necessarily be static, for we cannot
admit a passing onto higher orders which would leave
holes in the universal
fabric. And in any case between
even the most perfect of creatures and God an infinite
hiatus
must remain (
il y a l'infini entre Dieu et lui).
But Voltaire's objection regards, above all, the prin-
ciple of continuity, which is nowhere evidenced in
nature: let
the proof of that be that there are extinct
species in both the animal and
vegetable kingdoms.
It is probable that even among men there are
extinct
species; and between apes and men there is clearly
a gap. As
for spiritual substances, Christians believe
in them because faith teaches
that these substances
exist; but what reason had Plato for believing so?
And
finally how can there be in empty space a chain that
binds all?
Here Voltaire catches another difficulty in
the idea of a continuum,
namely, one owing something
to the philosophy of Newton, who had affirmed
the
existence of a vacuum—something rejected by Leibniz
in
favor of the plenitude hypothesis.
Of the two criticisms presented above, Johnson's in
its logical strictness
misses the mark because he chal-
lenges the
principle of plenitude precisely on the basis
of the idea that makes it
possible, namely the infinite
divisibility of matter. Voltaire's is the
more interesting
because it reflects the debates current in the
biological
sciences of his day, and especially the discussions of
the
notion of species, which, as we shall see, were to
be decisive in the
development and eventual dissolu-
tion of
the Chain of Being.