Just learned of a new liberal type of hermeneutic especially as it applies to the synoptic gospels. It's called redactive criticism. It apparently assumes that Mark's gospel is the primary if not only apostle authored gospel in that others used Mark's gospel adding to it or changing a few words here and there to convey a particular perspective of theology as that Christian theology grew. Most would deny inerrancy and also deny inspiration. Most would suggest that the gospels were all written post 70 AD except for mark. And most were suggesting that Matthew Luke and John were compiled by editors who added to Mark's text.

Here's a video which gives a beginning explanation of the system. It's sometimes compared against form criticism. It's apparently a new wave of liberal thinking in order to justify some people writing books.