The chief interest of the poem lies in the era of its conception, and in the fact that its composition alienated the horrors of his dungeon. At last he was set free. The duke of Orléans being informed of his innocence, he was liberated. The regent compensated for the mistake by a present of money. Voltaire, on thanking the regent, said, "I thank your royal highness for continuing to support me, but I entreat you not to burden yourself again with finding me a lodging." The genius and wit, however, of Voltaire, continued to expose him to calumny and danger. He was suspected of having written the "Philippiques," a clever, but most atrocious libel against the regent and his family. His frequent visits at Sceaux, the palace of the duchess de Maine, and his intimacy with Goerts, caused his name to be mingled in the intrigues which cardinal Alberoni excited in France. The regent, however, refused to credit his enemies, and limited his displeasure to an intimation that he had better absent himself from Paris for a time. Voltaire spent several months in going from one friend's chateau to another, being sedulously occupied, meanwhile, by the "Henriade" and other literary projects. The most important in his eyes was his tragedy of "Œdipus." [Sidenote: 1718. Ætat. 24.] This piece, commenced at eighteen, altered and altered again, was at last brought out, and had the greatest success. This was not solely caused by its intrinsic merit. The reputation of the author, its being his first tragedy, and the discussions to which it gave rise with regard to the ancient and modern theatre, imparted a factitious interest; it was attacked and defended on all sides, and pamphlets were daily published and hawked about on the subject. To these legitimate sources of interest were added the unworthy one of the calumnies in vogue against the duke of Orléans, which made the odious subject of the tragedy peculiarly piquante.[3] Voltaire wrote several letters on the treatment of his subject. His critique on the tragedies of Sophocles gives us, at once, the measure of his taste and learning: nothing can be more contemptible than either. The French _soi-disant_ poet was utterly incapable of entering into the solemn spirit of the Athenian tragedian, and still less could he comprehend his sublime poetry, being even ignorant of the language in which it was written. The "Œdipus Tyrannus" of Sophocles is admirable as a work of art, and more admirable from a certain majesty that sustains the subject and characters to the end, and from the solemn, magnificent beauty of the choruses. All this was a dead letter to the sprightly Parisian, who admits that had Sophocles lived in his days, he had written better, but had never approached the greatness of Racine.