But when Voltaire waxed enthusiastic over the princely periods at Brussels in the January of 1740 he had no premonition of that future. Compared with other royal compositions “Anti-Machiavelli” is a masterpiece. Even to one of the shrewdest men who ever breathed it might well have given hopes that its author would be a king not as other kings, a benefactor and not an oppressor of humanity, a defender of all liberal arts, a safeguard of justice, freedom, and civilisation. Old Frederick William was dying. The time was at hand when his son might make promise, practice. On June 6, 1740, he wrote to Voltaire: “My dear friend, my fate is changed, and I have been present at the last moments of a king, at his agony and at his death”; and prayed friend Voltaire to regard him not as king but as man. And Voltaire replied to him as “Your Humanity” instead of “Your Majesty,” and saw in the heavens the dawn of a golden day, and on earth all things made new.

On July 19th, Voltaire arrived at The Hague to see about recasting and correcting a new edition of the “Anti-Machiavelli,” now being printed there. There were certain things in it safe enough for a crown prince to have written anonymously, but hardly prudent to appear as the utterances of a king.

Voltaire was quite as active and thorough on that King’s behalf as on his own. He wasted a whole fortnight of his precious time on Frederick’s business in Holland. He had infinite trouble with the printer, Van Duren, and stooped to trickery (to be sure, Voltaire thought it no abasement) to get the necessary alterations made in the royal manuscript. At length this most indefatigable of beings himself brought out an authorised version of the “Anti-Machiavelli.” Voltaire’s corrected edition and Frederick’s original version both appear in a Berlin issue of the Works of King Frederick the Great. A comparison of the two shows the versatile Voltaire to be the most slashing and daring of editors. He cut out, as imprudent, as much as thirty-two printed pages of the royal composition. The time had not yet come when Frederick was grateful for such a hewing and a hacking as that. But the time was very soon to come when he would have been but too glad if Voltaire had flung into the fire the whole of “Anti-Machiavelli,” and the memory thereof.

The friendship between editor and author grew apace, meanwhile, daily. They sent each other presents of wine and infallible medicines. Voltaire had an escritoire, designed by Martin, specially made in Paris for Frederick’s acceptance. But they had long discovered that the handsomest of presents and the most adoring of letters were but a feeble bridge to span the space that separated them, and the question of a meeting, long and repeatedly urged by Frederick, became imminent.

Since Frederick’s first letter it had been the rôle of Madame du Châtelet to stand by and watch a comedy in which she was not offered a part. To be a passive spectator was little to the taste of her supremely energetic temperament. It was not long before she learnt to be jealous. She was a great deal too clever not to know from very early times that, but for her, Voltaire would have been a satellite to the Star of the North, instead of to any woman in the world. When his friendship with Frederick began he was no doubt true to her because he wished to be true. But how short a time was it before he was true only from a sense of duty! Madame du Châtelet, with her vigorous passions, was not the woman to be satisfied with a cold, conscientious affection like that. She must be first—everything! Her woman’s instinct told her to mistrust Frederick, and she did mistrust him. Then the mistrust grew to dislike; dislike to hate; and hate, war to the knife.

Oh what beautiful compliments that pair exchanged through Voltaire, or directly in the most flattering letters to each other—in those four years between 1736 and 1740! Frederick said the most charming things about Émilie. She was always the goddess, the sublime, the divine. Flattery costs so little and may buy so much.

When he read her “Essay on the Propagation of Fire,” he wrote to Voltaire that it had given him “an idea of her vast genius, her learning—and of your happiness.”

Did Madame look over her lover’s shoulder and smile not a little grimly with compressed lips at those last words? “Of your happiness”! Very well. Leave him to it then. What can your court or kingship give him better than happiness, after all? It is to be feared that if Émilie had rendered Voltaire’s life “un peu dure” in the time of Madame de Graffigny she rendered it much harder now, and that there was not much question of real happiness between them. To be fought over was a much more trying position for a nature like Voltaire’s than to be one of the fighters. And there is no hell on earth like that made by a jealous woman.

Within easy reach too, in tempting sight, were the pleasures of a king’s congenial society, honours to which a worldly-wise Voltaire could be by no means insensible. Yet in almost all his letters to Frederick he reiterates his decision that he will not leave his mistress; that he is bound to her in honour and gratitude; that he has chosen his fate and must abide by it.

In the spring of 1740 she had published her “Institutions Physiques,” in which she now championed Leibnitz against Newton, as Voltaire had championed Newton against Leibnitz. Frederick went into ecstasies over it—to its authoress; and damned it with very faint praise indeed to his confidant, Jordan. Madame may have suspected that perfidy. King Frederick, when he became king in that May of 1740, guessed he had met his match in that resolute woman whom he addressed variously as “Venus Newton” and the “Queen of Sheba.” If Frederick wanted to see Voltaire—well, then, he must have Venus too. Of that, Venus was determined. Voltaire returned to Brussels from The Hague in the early days of August, 1740. It was not the slightest use Frederick’s writing to him on the 5th of that month from Berlin: “To be frank ... it is Voltaire, it is you, it is my friend whom I desire to see, and the divine Émilie with all her divinity is only an accessory to the Newtonian Apollo”; and more plainly still the next day, “If Émilie must come with Apollo, I agree; although I would much rather see you alone.” Madame du Châtelet was for Voltaire a sovereign far more absolute than any on earth. He pulled a very wry face, shrugged his shoulders, and resigned himself to her determination with as much good-humour and nonchalance as he could compass. It was arranged that Frederick should meet Voltaire and Venus at Antwerp on September 14th, and should return with them for a brief visit, incognito, to the du Châtelet’s hired house in Brussels.