The study of the Gospels may be divided here for convenience into two branches, which may be called Textual Criticism and Introduction. Under the head of Introduction we may group all those questions with the first appearance of a book, such as the date, place of publication, the authorship, and the sources known to or used by the author. Under the head of Textual Criticism comes the history of the book from the time it left the author’s hands to the present day, including the study not only of accidental errors introduced by copyists, but also of the work of later editors and revisers. – From the Introduction