One main motive of Bossuet in his lifelong concern for Providence was his conviction that the doctrine was the most powerful check on immorality, and that to deny it was to remove the strongest restraint on the evil side of human nature. There is no doubt that the free-living people of the time welcomed the arguments which called Providence in question, and Bossuet believed that to champion Providence was the most efficient means of opposing the libertine tendencies of his day. "Nothing," he declared in one of his sermons (1662), "has appeared more insufferable to the arrogance of libertines than to see themselves continually under the observation of this ever-watchful eye of Providence. They have felt it as an importunate compulsion to recognise that there is in Heaven a superior force which governs all our movements and chastises our loose actions with a severe authority. They have wished to shake off the yoke of this Providence, in order to maintain, in independence, an unteachable liberty which moves them to live at their own fancy, without fear, discipline, or restraint." [Passage from Bossuet, quoted by Brunetiere, op. cit. 58.] Bossuet was thus working in the same cause as the Jansenists. He had himself come under the influence of Descartes, whose work he always regarded with the deepest respect. 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. [Footnote: Fenelon's Refutation of Malebranche's Traite de la nature et de la grace was not published till 1820. This work of Malebranche also provoked a controversy with Arnauld, who urged similar arguments.]