PAUL THIET, BARON D', a French philosopher of the eighteenth century, was born in 1723 at Heidelberg, in the Palatinate. He was brought up in Paris, spent the greater part of his life in that city, and died there in 1789. His name has been saved from oblivion more from his connection with the French encyclopaedists, and his judicious patronage of rising literary merit, than from the intrinsic merit of his own works, though these are very numerous. His house in Paris was the rendezvous of those spirits whom Mme. Geoffrin had found too daring to receive at her philosophical dinners, and for forty years was the centre and hot-bed of the new philosophy of which Diderot, Helvetius, and Grimm were the chief apostles. D'Holbach was a man of considerable means, of which, he expended no small part on the pleasures of the table; and it was believed that the good cheer of the baron's board was quite as attractive to his guests as his own conversation. The baron himself was a freethinker of the lowest type, and as much an atheist as a man can be. Like most persons of that stamp he was superstitious, and as credulous as a child. His materialism was of so gross a kind that some of the finer spirits of the age eschewed his society altogether. The discreet D'Alembert shunned him; Buffon maintained a haughty reserve; and J. J. Rousseau openly quarrelled with him. Much interesting gossip about the baron and his connection with the new opinions is to be found in Grimm's Correspondence. Besides contributing largely to Diderot's Encyclopédie, D'Holbach wrote a Système de la Nature, which Voltaire condemned, and with good reason, as "bad in diction, absurd in philosophy, and execrable in morals." The work is indeed villainous in its purport, and one of the most unblushing and flagrant attacks ever made on morality; but it is so excessively pointless, diffuse, and ill-argued as to be comparatively harmless. Still worse, if possible, is his Christianisme Dévoilé (Christianity unmasked), the object and the ultimate fate of which were nearly the same as those of the work already mentioned. All these works are now happily forgotten.