Historical Jesus
One of the most critical criteria for establishing the historical Jesus is the criterion of multiple attestation, that is, the description or saying of Jesus is attested in multiple, independent sources. For instance, in John Meier's work, "A Marginal Jew: Rethinking the Historical Jesus", Meier identifies four independent sources for reconstructing the historical Jesus within the New Testament: Q, Mark, Paul, and John. Historical Jesus scholars using the four-source hypothesis have even more independent sources at their disposal; in addition to Q, Mark, Paul, and John, they have the M-Source and the L source. Some scholars also include Agrapha and Apocryphal gospels, such as the Gospel of Thomas. (Most scholars consider these to be dependent upon the Canonical gospels, however.)