Leibniz wrote two books; a considerable number of articles in learned
periodicals; and an enormous number of unpublished notes, papers and
letters, preserved in the archives of the Electors of Hanover not because
of the philosophical significance of some of them, but because of the
political importance of most of them. From among this great mass various
excerpts of philosophical interest have been made by successive editors of
Leibniz's works. It may be that the most profound understanding of his mind
is to be derived from some of these pieces, but if we wish to consider the
public history of Leibniz, we may set them aside.
Of the two books, one was published, and the other never was. The _New
Essays_ remained in Leibniz's desk, the _Theodicy_ saw the light. And so,
to his own and the succeeding generation, Leibniz was known as the author
of the _Theodicy_.
The articles in journals form the immediate background to the two books. In
1696 Leibniz heard that a French translation of Locke's _Essay concerning
Human Understanding_ was being prepared at Amsterdam. He wrote some polite
comments on Locke's great work, and published them. He also sent them to
Locke, hoping that Locke would write a reply, and that Leibniz's reflexions
and Locke's reply might be appended to the projected French translation.
But Locke set Leibniz's comments aside. Leibniz, not to be defeated, set to
work upon the _New Essays_, in which the whole substance of Locke's book is
systematically discussed in dialogue. The _New Essays_ were written in
1703. But meanwhile a painful dispute had broken out between Leibniz [34]
and the disciples of Locke and Newton, in which the English, and perhaps
Newton himself, were much to blame, and Leibniz thought it impolitic to
publish his book. It was not issued until long after his death, in the
middle of the century.
The discussion with Locke was a failure: Locke would not play, and the book
in which the whole controversy was to be systematized never appeared. The
discussion with Bayle, on the other hand, was a model of what a discussion
should be. Bayle played up tirelessly, and was never embarrassingly
profound; he provided just the sort of objections most useful for drawing
forth illuminating expositions; he was as good as a fictitious character in
a philosophical dialogue. And the book in which the controversy was
systematized duly appeared with great éclat.
Here is the history of the controversy. In 1695 Leibniz was forty-nine
years old. He had just emerged from a period of close employment under his
prince's commands, and he thought fit to try his metaphysical principles
upon the polite world and see what would come of it. He therefore published
an article in the _Journal des Savants_ under the title: 'New System of
Nature and of the Communication of Substances, as well as of the Union
between Soul and Body'. In the same year Foucher published an article in
the _Journal_ controverting Leibniz; and in the next year Leibniz replied
with an 'Explanation'. A second explanation in the same year appeared in
Basnage's _Histoire des Ouvrages des Savants_, in answer to reflexions by
the editor. M. Pierre Bayle had all these articles before him when he
inserted a note on Leibniz's doctrine in his article on 'Rorarius', in the
first edition of his _Historical and Critical Dictionary_. The point of
connexion between Rorarius and Leibniz was no more than this, that both
held views about the souls of beasts.
Pierre Bayle was the son of a Calvinist pastor, early converted to
Catholicism, but recovered to his old faith after a short time. He held
academic employments in Switzerland and Holland; he promoted and edited the
_Nouvelles de la République des Lettres_, and he produced that
extraordinary work the _Historical and Critical Dictionary._ The notices it
contains of authors and thinkers are little more than pegs upon which Bayle
could hang his philosophical reflexions. He could write an intelligent
discussion on any opinion; what he could not do was to reconcile the points
of view from which he felt impelled to write upon this author and that.[35]
His was not a systematic mind. So far as he had a philosophical opinion, he
was a Cartesian; in theology he was an orthodox Calvinist. He could not
reconcile his theology with his Cartesianism and he did not try to. He made
a merit of the oppositions of faith to reason and reason to itself, so that
he could throw himself upon a meritorious and voluntary faith.
There is nothing original in this position. It was characteristic of
decadent scholasticism, it squared with Luther's exaggerations about the
impotence of reason in fallen man, and Pascal had given his own highly
personal twist to it. Bayle has been hailed as a forerunner of Voltairean
scepticism. It would be truer to say that a Voltairean sceptic could read
Bayle's discussions in his own sense and for his own purposes if he wished.
But Bayle was not a sceptic. It is hard to say what he was; his whole
position as between faith and reason is hopelessly confused. He was a
scholar, a wit, and a philosophical sparring-partner of so perfectly
convenient a kind that if we had not evidence of his historical reality, we
might have suspected Leibniz of inventing him.
In the first edition of his _Dictionary_, under the article 'Rorarius',
Bayle gave a very fair account of Leibniz's doctrine concerning the souls
of animals, as it could be collected from his article in the _Journal des
Savants_, 27 June 1695. He then proceeded to comment upon it in the
following terms:
'There are some things in Mr. Leibniz's hypothesis that are liable to some
difficulties, though they show the great extent of his genius. He will have
it, for example, that the soul of a dog acts independently of outward
bodies; that _it stands upon its own bottom, by a perfect _spontaneity_
with respect to itself, and yet with a perfect _conformity_ to outward
things_.... That _its internal perceptions arise from its original
constitution, that is to say, the representative constitution (capable of
expressing beings outside itself in relation to its organs) which was
bestowed upon it from the time of its creation, and makes its individual
character_ (_Journal des Savants_, 4 July 1695). From whence it results
that it would feel hunger and thirst at such and such an hour, though there
were not any one body in the universe, and _though nothing should exist but
God and that soul_. He has explained (_Histoire des Ouvrages des Savants_,
Feb. 1696) his thought by the example of two pendulums that should
perfectly agree: that is, he supposes that according to the particular laws
which put the soul upon action, it must feel hunger at such an hour; [36]
and that according to the particular laws which direct the motion of
matter, the body which is united to that soul must be modified at that same
hour as it is modified when the soul is hungry. I will forbear preferring
this system to that of occasional causes till the learned author has
perfected it. I cannot apprehend the connexion of internal and spontaneous
actions which would have this effect, that the soul of a dog would feel
pain immediately after having felt joy, though it were alone in the
universe. I understand why a dog passes immediately from pleasure to pain
when, being very hungry and eating a piece of bread, he is suddenly struck
with a cudgel. But I cannot apprehend that his soul should be so framed
that at the very moment of his being beaten he should feel pain though he
were not beaten, and though he should continue to eat bread without any
trouble or hindrance. Nor do I see how the spontaneity of that soul should
be consistent with the sense of pain, and in general with any unpleasing
perceptions.
'Besides, the reason why this learned man does not like the Cartesian
system seems to me to be a false supposition; for it cannot be said that
the system of occasional causes brings in God acting by a miracle (ibid.),
_Deum ex machina_, in the mutual dependency of the body and soul: for since
God does only intervene according to general laws, he cannot be said to act
in an extraordinary manner. Does the internal and active virtue
communicated to the forms of bodies according to M. Leibniz know the train
of actions which it is to produce? By no means; for we know by experience
that we are ignorant whether we shall have such and such perceptions in an
hour's time. It were therefore necessary that the forms should be directed
by some internal principle in the production of their acts. But this would
be _Deus ex machina,_ as much as in the system of occasional causes. In
fine, as he supposes with great reason that all souls are simple and
indivisible, it cannot be apprehended how they can be compared with a
pendulum, that is, how by their original constitution they can diversify
their operations by using the spontaneous activity bestowed upon them by
their Creator. It may clearly be conceived that a simple being will always
act in a uniform manner, if no external cause hinders it. If it were
composed of several pieces, as a machine, it would act different ways,
because the peculiar activity of each piece might change every moment the
progress of others; but how will you find in a simple substance the [37]
cause of a change of operation?'
Leibniz published a reply to Bayle in the _Histoire des Ouvrages des
Savants_ for July 1698. As in all his references to Bayle, he is studiously
polite and repays compliment for compliment. The following are perhaps the
principal points of his answer.