’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.

1.  On the example of the dog: 

(a) How should it of itself change its sentiment, since everything left to itself continues in the state in which it is?  Because the state may be a state of change, as in a moving body which, unless hindered, continues to move.  And such is the nature of simple substances—­they continue to evolve steadily.

(b) Would it really feel as though beaten if it were not beaten, since Leibniz says that the action of every substance takes place as though nothing existed but God and itself?  Leibniz replies that his remark refers to the causality behind an action, not to the reasons for it.  The spontaneous action of the dog, which leads to the feeling of pain, is only decreed to be what it is, for the reason that the dog is part of a world of mutually reflecting substances, a world which also includes the cudgel.

(c) Why should the dog ever be displeased spontaneously?  Leibniz distinguishes the spontaneous from the voluntary:  many things occur in the mind, of itself, but not chosen by it.

2.  On Cartesianism and miracle: