Voltaire's envy and jealousy were now turned against the Marquis d'Argens, who was indeed the dearest friend of the king. At first he tried to prejudice the king against him; he betrayed to him that the marquis had privately married the actress Barbe Cochois.
The king was at the moment very angry, but the prayers of Algarotti, and the regret of the poor marquis, reconciled him at last; he not only forgave, but he allowed the marquise to dwell at Sans-Souci with her husband.
When Voltaire found that he could not deprive the marquis of the king's favor, he resolved to occasion him some trouble, and to wound his vanity and sensibility. He knew that the marquis was an ardent admirer of the French writer Jean Baptiste Rousseau. One day Voltaire entered the room of the marquis, and said, in a sad, sympathetic tone, that he felt it his duty to undeceive him as to Jean Baptiste Rousseau, to prove to him that his love and respect for the great writer were returned with the blackest ingratitude. He had just received from his correspondent at Paris an epigram which Rousseau had made upon the marquis. It was true the epigram was only handed about in manuscript, and Rousseau swore every one who read it not to betray him; he was showing it, however, and it was thought it would be published. He, Voltaire, had commissioned his correspondent to do every thing in his power to prevent the publication of this epigram; or, if this took place, to use every means to excite the public, as well as the friends of the marquis, against Rousseau, because of his shameful treachery.
At all events, this epigram, which Voltaire now read aloud. to the marquis, and which described him as the Wandering Jew, was as malicious as it was mischievous and slanderous. The good marquis was deeply wounded, and swore to take a great revenge on Rousseau. Voltaire triumphed.
But, after a few days, he suspected that the whole was an artifice of Voltaire. In accordance with his open, noble character, he wrote immediately to Rousseau, made his complaint, and asked if he had written the epigram.
Rousseau swore that he was not the author, but he was persuaded that Voltaire had written it; he had sent some copies to Paris, and his friends were seeking to spread it abroad. [Footnote: Thiebault.]
The marquis was on his guard, and did not communicate this news to Voltaire. He resolved to escape from these assaults and intrigues quietly; with his young wife he made a journey to Paris, and did not return till Voltaire had left Berlin forever.
The most powerful and therefore the most abhorred of the enemies against whom Voltaire now turned in his rage, was the president of the Berlin Academy, Maupertius. Voltaire could never forgive him for daring to shine in his presence; for being the president of an academy of which he, Voltaire, was only a simple member. Above all this, the king loved him, and praised his extraordinary talent and scholarship. Voltaire only watched for an opportunity to clutch this dangerous enemy, and the occasion soon presented itself.
Maupertius had just published his "Lettres Philosophiques," in which it must be confessed there were passages which justified Voltaire's assertion that Maupertius was at one time insane, and was confined for some years in a madhouse at Montpellier. Maupertius proposed in these letters that a Latin city should be built, and this majestic and beautiful tongue brought to life again. He proposed, also, that a hole should be dug to the centre of the earth, in order to discover its condition and quality; also that the brain of Pythagoras should be searched for and opened, in order to ascertain the nature of the soul.
These ridiculous and fabulous propositions Voltaire replied to under the name of Dr. Akakia; he asserted that he was only anxious to heal the unhappy Maupertius. This publication was written in Voltaire's sharpest wit and his most biting, glittering irony, and was calculated to make Maupertius absurd in the eyes of the whole world.