When form criticism questioned the historical reliability of the Gospels, scholars began looking for other criteria. Taken from other areas of study such as source criticism, the "criteria of authenticity" emerged gradually, becoming a distinct branch of methodology associated with life of Jesus research. The "criteria" are a variety of rules used to determine if some event or person is more or less likely to be historical. These criteria are primarily, though not exclusively, used to assess the sayings and actions of Jesus. In view of the skepticism produced in the mid-twentieth century by form criticism concerning the historical reliability of the gospels, the burden shifted in historical Jesus studies from attempting to identify an authentic life of Jesus to attempting to prove authenticity. The criteria developed within this framework, therefore, are tools that provide arguments solely for authenticity, not inauthenticity. In 1901, the application of criteria of authenticity began with dissimilarity. It was often applied unevenly with a preconceived goal. In the early decades of the twentieth century, F.C. Burkitt and B.H. Streeter provided the foundation for multiple attestation. The Second Quest introduced the criterion of embarrassment. By the 1950s, coherence was also included. By 1987, D.Polkow lists 25 separate criteria being used by scholars to test for historical authenticity including the criterion of "historical plausibility". A number of scholars have criticized the various approaches used in the study of the historical Jesus—on one hand, for the lack of rigor in research methods; on the other, for being driven by "specific agendas" that interpret ancient sources to fit specific goals. By the 21st century, the "maximalist" approaches of the 19th century, which accepted all the gospels, and the "minimalist" trends of the early 20th century, which totally rejected them, were abandoned and scholars began to focus on what is historically probable and plausible about Jesus. There is widespread disagreement among scholars on the details of the life of Jesus mentioned in the gospel narratives, and on the meaning of his teachings. Scholars differ on the historicity of specific episodes described in the biblical accounts of Jesus, but almost all modern scholars consider his baptism and crucifixion to be historical facts. The existence of John the Baptist within the same time frame as Jesus, and his eventual execution by Herod Antipas is attested to by 1st-century historian Josephus and the overwhelming majority of modern scholars view Josephus' accounts of the activities of John the Baptist as authentic.