Mani himself was the author of several works:  a Gospel, the Treasury of Life (and probably an abridgment of the same), the Mysteries, the Foundation Fpistle, a book of Articles or heads of doctrine, one or two works on astronomy or astrology, and a collection of letters so dangerous, that Manichæans who sought restoration to the Church were required to anathematize them. Probably the most important of these writings was the Foundation Epistle, so called because it contained the leading articles of doctrine on which the new system was built.  This letter was written in Greek or Syriac; but a Latin version of it was current in Africa, and came into the hands of Augustin, who undertook its refutation.  To accomplish this with the greater precision and effect, he quotes the entire text of each passage of the Epistle before proceeding to criticise it.  Had Augustin accomplished the whole of his task, we should accordingly have been in possession of the whole of this important document.  Un- fortunately, for reasons unknown, Augustin stops short at an early point in the Epistle; and though he tells us he had notes on the remainder, and would some day expand and publish them, this promise lay unredeemed for thirty years till the day of his death.  Extracts from the same Epistle and from the Treasury are also given by Augustin in the treatise De Natura Boni.31 35 Next, we have in the Opus Imperfectum of Augustin some extracts from a letter of Mani to Menoch, which Julian had unearthed and republished to convict Augustin of being still tainted with Manichæan sentiments.  These extracts give us some insight into the heresiarch’s opinions regarding the corruption of nature and the evils of sexual love. Again, we have Mani’s letter to Marcel, preserved by Epiphanius, and given in full by Beausobre;32 which, however, merely reiterates two of the doctrines most certainly identified with Mani,—the assertion of two principles, and the tenet that the Son of God was man only in appearance. Finally, Fabricius has inserted in the fifth volume of his Bibliotheca Græca the fragments, such as they are, collected by Grabe. Such is the fragmentary character of the literary remains of Mani:  for fuller information regarding his opinions we must depend on Theodoret, Epiphanius, Alexander of Lycopolis, Titus of Bostra, and Augustin.  Beausobre is of opinion that the Fathers derived all that they 31 The De Natura Boni, written in the year 405, is necessarily very much a reproduction of what is elsewhere affirmed, that all natures are good, and created by God, who alone is immutable and incorruptible.  It presents concisely the leading positions of Augustin in this controversy, and concludes with an eloquent prayer that his efforts may be blessed to the conversion of the heretics,—not the only passage which demonstrates that he wrote not for the glory of victory so much as for the deliverance of men from fatal error. 32 Histoire, i. 91. 49 Preface to the Anti-Manichæan Writings.