In much of the recent discussion about the revival of the GH, attention has been focussed on the relationship between Mark and the other two synoptic gospels. However, another important assertion of the GH is that Luke is directly dependent on Matthew. Now it would be quite possible to believe that Mark conflated Matthew and Luke without necessarily believing that Luke knew Matthew. Indeed precisely this position was adopted by de Wette and Bleek in the nineteenth century. Both believed that a direct literary relationship between Matthew and Luke was excluded by the fact that neither of these two gospels consistently gave the more original tradition. Nevertheless, the two issues, i.e. the relationship between Matthew and Luke, and the relative position of Mark, are not completely separate. If there is a common source behind Matthew and Luke, there is the possibility of this source overlapping with Mark, and hence of accounting for some of the agreements between Matthew and Luke against Mark. On the other hand, if it could be shown that Luke knew and used Matthew in ‘double tradition’ passages, the same explanation might account for the agreements in passages where there is a Markan parallel as well. The theory of Luke's dependence on Matthew also plays a vital hidden role within Farmer's total argument for the GH. The phenomenon of order, in particular the fact that Matthew and Luke do not agree against Mark in this respect, is regarded by Farmer as giving decisive support to the GH.