The cautiousness of the master had done much to disguise the insidious dangers of his thought, and it was in the hands of those disciples who developed his system and sought to reconcile it at all points with orthodoxy that his ideas displayed their true nature.

Malebranche's philosophy revealed the incompatibility of Providence--in the ordinary acceptation--with immutable natural laws.
If the Deity acts upon the world, as Malebranche maintained, only by means of general laws, His freedom is abolished, His omnipotence is endangered, He is subject to a sort of fatality.

What will become of the Christian belief in the value of prayers, if God cannot adapt or modify, on any given occasion, the general order of nature to the needs of human beings?
These are some of the arguments which we find in a treatise composed by Fenelon, with the assistance of Bossuet, to demonstrate that the doctrine of Malebranche is inconsistent with piety and orthodox religion.

They were right.

Cartesianism was too strong a wine to be decanted into old bottles.