"But before we consider the Gospels individually, two further special difficulties have to be mentioned. First they cannot be checked effectively from other sources. The assistance provided by pagan literature, in particular, is meagre indeed. References to the Christians in Tacitus, Suetonius and Pliny the younger are a good deal later, and in any case they throw little or no light on the life of Jesus himself. The Jewish evidence, too, notably in the Talmud, comes from a subsequent period, and some of the Talmud passages are based on Christian sources, so that they carry no independent weight." Michael Grant, Jesus: An Historian's Review of the Gospels (New York: Collier, 1977), p. 183.