(d) _Verbal differences._--Striking verbal differences occur even when the general resemblance is most close. In Matt. ix. 1-17, Mark ii. 1-22, Luke v. 17-39, there are verbal changes even where the sentences closely coincide. Other instances might be quoted. All three evangelists have a style of their own, and show a marked preference for particular idioms and words. In narrating the sayings of our Lord, they narrate them with some verbal differences, and in the case of the history of His ministry, they narrate it with numerous verbal differences. It is therefore evident that St. Matthew and St. Luke, if they used St. Mark's work, felt themselves at liberty to deal with it very freely. The above brief account of the chief resemblances and differences between the first three Gospels is an attempt to give a fair though condensed statement of certain facts which appeal with different force to different minds. "How came these Gospels to be so alike and yet so different?" This is the "Synoptic problem," and great divergence of opinion exists as to the solution. [Sidenote: Possible solutions.] The most important views propounded to solve the problem are-- (1) Both St. Matthew and St. Luke copied the Gospel of St. Mark, while not omitting to make use of other documents. In the case of St. Luke, his acquaintance with earlier written stories about our Lord is rendered indisputable by his own statement. Sometimes it has been thought that St. Luke made use of the Gospel according to St. Matthew as well as the Gospel according to St. Mark. This theory is most appropriately called the _theory of the mutual dependence of the documents_. (2) The three Synoptic Gospels put down in writing different, but closely similar forms of an oral tradition concerning the teaching of our Lord. It is thought that the statements made by the apostles about Christ were repeated by them and occasionally added to, and treasured up in faithful memories. {21} The idea of a _literary_ connection between the Gospels is dismissed, and it is held that the methods of teaching employed among the Jews, and the probable existence of a school of trained catechists, will account sufficiently for the fixed form of the tradition. According to this hypothesis the differences between the Synoptic Gospels are to be explained by the necessity of teaching different aspects of the truth among different classes of inquirers, and by the fluctuating memories of the teachers. This theory is known as the _oral theory_.[3]