Where the original documents have been lost, as has happened with all the books of the Bible, the original wording must be ascertained, as far as possible, by a critical comparison of the surviving copies. This operation is known as textual criticism. It is plainly an operation of basic importance, for until we have established the original wording with reasonable certainty, we cannot proceed to further lines of study which depend to a large extent on the precise wording of the text. For this reason