many details of his life. The reports of supernatural events associated with Jesus' death and resurrection make the challenge even more difficult. Scholars regard the Gospels as compromised sources of information because the writers were trying to glorify Jesus. Even so, the sources for Jesus' life are better than sources scholars have for the life of Alexander the Great. Scholars use a number of criteria, such as the criterion of independent attestation, the criterion of coherence, and the criterion of discontinuity to judge the historicity of events. The historicity of an event also depends on the reliability of the source; indeed, the Gospels are not independent nor consistent records of Jesus' life. Mark, which is most likely the earliest written gospel, has been considered for many decades the most historically accurate. John, the latest written gospel, differs considerably from the Synoptic Gospels, and thus is generally considered less reliable, although more and more scholars now also recognize that it may contain a core of older material as historically valuable as the Synoptic tradition or even more so. Some scholars (most notably the Jesus Seminar) believe that the non-canonical Gospel of Thomas might be an independent witness to many of Jesus' parables and aphorisms. For example, Thomas confirms that Jesus blessed the poor and that this saying circulated independently before being combined with similar sayings in the Q source. However, the majority of scholars are skeptical about this text and believe it should be dated to the 2nd century CE instead. Other select non-canonical Christian texts may also have value for historical Jesus research. Early non-Christian sources that attest to the historical existence of Jesus include the works of the historians Josephus and Tacitus. Josephus scholar Louis Feldman has stated that "few have doubted the genuineness" of Josephus's reference to Jesus in book 20 of the Antiquities of the Jews, and it is disputed only by a small number of scholars. Tacitus referred to Christ and his execution by Pilate in book 15 of his work Annals. Scholars generally consider Tacitus's reference to the execution of Jesus to be both authentic and of historical value as an independent Roman source. Non-Christian sources are valuable in two ways. First, they show that even neutral or hostile parties never show any doubt that Jesus actually existed. Second, they present a rough picture of Jesus that is compatible with that found in the Christian