 In 1838, two theologians, Christian Gottlob Wilke and Christian Hermann Weisse, independently extended Lachmann's reasoning to conclude that Mark not only best represented Matthew and Luke's source but also that Mark was Matthew and Luke's source.Their ideas were not immediately accepted, but Heinrich Julius Holtzmann's endorsement in 1863 of a qualified form of Marcan priority won general favor.There was much debate at the time over whether Matthew and Luke used Mark itself or some Proto-Mark (Ur-Mark).