To the hatred of the devotees was joined that of his rivals for glory. This was rekindled by a work of La Mettrie's entitled "The Politics of Physicians." A man full of cunning, and carried away by ambition, aspired to the place, then vacant, of first physician to the king of France. He thought that he could gain it by heaping ridicule upon those of his contemporaries who might lay claim to this position. He wrote a libel against them, and abusing the easy friendship of La Mettrie, he enticed him to lend to it the volubility of his pen, and the richness of his imagination. Nothing more was needed to complete the downfall of a man little known, against whom were all appearances, and whose only protection was his merit. For having been too sincere as a philosopher and too obliging as a friend, La Mettrie was compelled to leave his country. The Duke of Duras and the Viscount of Chaila advised him to flee from the hatred of the priests and the revenge of the physicians. Therefore, in 1746, he left the hospitals of the army where he had been placed by M. Sechelles, and came to Leyden to philosophize in peace. He there composed his "Penelope," a polemical work against the physicians in which, after the fashion of Democritus, he made fun of the vanity of his profession. The curious result was that the doctors themselves, though their quackery was painted in true colors, could not help laughing when they read it, and that is a sure sign that they had found more wit than malice in it. M. La Mettrie after losing sight of his hospitals and his patients, gave himself up completely to speculative philosophy; he wrote his "Man a Machine" or rather he put on paper some vigorous thoughts about materialism, which he doubtless planned to rewrite. This work, which was bound to displease men who by their position are declared enemies of the progress of human reason, roused all the priests of Leyden against its author. Calvinists, Catholics and Lutherans forgot for the time that consubstantiation, free will, mass for the dead, and the infallibility of the pope divided them: they all united again to persecute a philosopher who had the additional misfortune of being French, at a time when that monarchy was waging a successful war against their High Powers. The title of philosopher and the reputation of being unfortunate were enough to procure for La Mettrie a refuge in Prussia with a pension from the king. He came to Berlin in the month of February in the year 1748; he was there received as a member of the Royal Academy of Science. Medicine reclaimed him from metaphysics, and he wrote a treatise on dysentery, another on asthma, the best that had then been written on these cruel diseases. He sketched works on certain philosophical subjects which he had proposed to look into. By a sequence of accidents which befell him these works were stolen, but he demanded their suppression as soon as they appeared.