Preface. ———————————— The Ante-Nicene Fathers , which seemed many years ago to have completed its task, now presents itself once more and ventures to solicit the renewal of the favour with which it was formerly received by the theological world.  The publishers and the editor, who now stands, he well knows how unworthily, in the place of Principal Donaldson and Professor Roberts, believe that the volume now added to the series will be found most interesting in itself and not unworthy to stand beside its predecessors. This volume consists of two distinct parts.  The first is a collection of recently discovered additions to early Christian literature.  The period which has elapsed since the last volumes of this series were published has been singularly rich in such discoveries.  A portion of a gospel has been recovered which was read in the latter part of the second century in certain Christian churches and purports to be the work of the Apostle Peter.  A harmony of the four canonical gospels has also been brought to our knowledge, which was made in the same century, and which, in a considerable district of Eastern Christendom, supplanted these gospels themselves.  Another work bearing the name of the Apostle Peter, his Apocalypse, which once appeared to have some claim to a place in the canon, has also been found.  The Epistles of Clement, which formerly broke off abruptly, have recovered their concluding portions, and the earliest public appeal to the head of the state on behalf of Christianity is also now in our possession.  The circumstances of these various discoveries, and also of others of a similar nature, are stated in the introductions prefixed by the writers in this volume to the various pieces, and it will be seen that scholars of many lands have taken part in them.  English scholarship, it is well known, has distinguished itself highly in this field.  Many of the pieces now given first saw the light in the Cambridge Texts and Studies , a publication of singular interest and enduring value, without which the present volume would not have come into existence.  The editor of the Texts and Studies , Professor Armitage Robinson, has taken a very kind interest in the present publication and has himself contributed translations of two pieces. The history of the discussions awakened by these discoveries cannot yet be written, but it is not too early to place the English reader in possession of the documents thus restored to the Christian community.  The reader of former volumes of The Ante-Nicene Fathers has already become acquainted with a number of uncanonical gospels, of apocalypses, and of early Christian apologies.  In each of these classes of Christian literature he is now presented with pieces not less interesting than any known before.  A glance at the table of contents will show the principle according to which the various works have been arranged.  It may be stated that the Diatessaron of Tatian is here for the first time translated into English from the Arabic. The second part of this volume contains portions of two of the most important commentaries of Origen.  When The Ante-Nicene Fathers came to a close it was felt that more should have been done for a father who occupies a position of such singular importance in the history both of Scripture exegesis and of Christian thought.  It is believed that the present translations will be welcomed by many who feel that growing interest in Origen which now appears in many quarters, and that they will be acceptable to all who care to know the varieties of treatment the Scriptures have met with in the church.