'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: