Voltaire read and read again with delight, and plied the writer with reiterated exhortations in every key, not to allow himself to be driven from the great work by the raging of the heathen and the vain imaginings of the people.[140] While the storm seemed to be at its height, an incident occurred which let loose a new flood of violent passion.

Helvetius published that memorable book in which he was thought to have told all the world its own secret.

His _De l'Esprit_ came out in 1758.[141] It provoked a general insurrection of public opinion.

The devout and the heedless agreed in denouncing it as scandalous, licentious, impious, and pregnant with peril.

The philosophic party felt that their ally had dealt a sore blow to liberty of thought and the free expression of opinion.
"Philosophy," said Grimm, by philosophy, as I have said, meaning Liberalism, "will long feel the effect of the rising of opinion which this author has caused by his book; and for having described too freely a morality that is bad and false in itself, M.Helvetius will have to reproach himself with all the restraints that are now sure to be imposed on the few men of lofty genius who still are left to us, whose destiny was to enlighten their fellows, and to spread truth over the earth."[142] At the beginning of 1759 the procureur-general laid an information before the court against Helvetius's book, against half a dozen minor publications, and finally against the Encyclopaedia.