Jean Baptiste de Mirabaud was born at Paris, in the year 1675. Of his early life we can glean but very scanty information. He appears first to have embraced the military profession, but it not being consonant with his general character, he soon quitted the army, and devoted himself to literature. He was, however, nearly forty-nine years of age before he became known in the literary world. He then published a French translation of Tasso's "Jerusalem," which brought him much fame; and many of the contributors to the French Encyclopaedia appear to have associated with him, and courted his friendship. He was afterwards elected a member of the French Academy of which he became the Secretary in 1742. Mirabaud was a constant visitor at the house of his friend, the Baron d'Holbach, down to the period of his death. He wrote "The World: its Origin and its Antiquity," "Opinions of the Ancients upon the Jews," "Sentiments of the Philosophers upon the Nature of the Soul," and other minor works. The "System of Nature" was also for many years attributed to Mirabaud, but it appears now to be extremely doubtful whether he ever wrote a single line of the work. The Abbe Galiani was one of the first who pointed out D'Holbach as the author. In the memoirs of M. Suard, edited by M. Garat, the same hypothesis is supported with additional firmness. Dugald Stewart seems to put much faith in the latter authority, as fixing the authorship of the "System of Nature" upon D'Holbach. Voltaire attributes the work to Damilaville, in a somewhat positive manner, for which he is sharply criticised in the "Biographie Universelle," published in 1817. The "System of Nature" is a book of which Dugald Stewart speaks, as "the boldest, if not the ablest work of the Parisian Atheists," and it has undoubtedly obtained great popularity. Voltaire, who has written against the "System of Nature" in a tone of bitter sarcasm, and who complains of its general dullness and prolixity, yet admits that it is "often humorous, sometimes eloquent." It certainly is not written in that lively, but rather superficial style, which has characterized many of the French writers, but it speaks in plain yet powerful language, evincing an extensive acquaintance with the works of previous philosophers, and much thought in relation to the subjects treated upon. Some of its pages exhibiting more vivacity than the rest of the book, have been attributed to Diderot, who (it is alleged by Marmontel and others) aided, by his pen and counsel, many of the Freethinking works issued during his life. The "System of Nature" was not published during the life-time of Mirabaud, and it is therefore impossible to use any argument which might have been based upon Mirabaud's conduct in relation to it.