The great innovation of Azariah dei Rossi was his reliance on non-Jewish sources in his investigation of Jewish history. He was bold, challenging the historical accuracy of rabbinic texts and citing the historians of ancient Greece and Rome, as well as the Christian scriptures and many great figures of the Middle Ages and the Renaissance. He carefully weighed the evidence in his probe into Jewish history and he understood that many Talmudic legends that dealt with events in the Jewish past were precisely that—they were legends. For his time, Azariah was a rebel. Although he never abandoned Jewish faith and practice, he set the stage for a new understanding of Jewish history that broke with the past. The rabbinic texts that cited historical events and figures were legends that attempted to teach a theological lesson. Most of the time, these texts were not historically accurate. When the Talmud tells us that Titus, the Roman general who destroyed Jerusalem in the year 70, dies when an insect entered through his nose and ate away at his brain, this is a theological lesson teaching that God punishes the enemies of the Jewish people. Azariah could not accept the historicity of this legend and relied upon ancient pagan historians for his discussion of the death of Titus. This was the first attempt since Josephus to write Jewish history unconnected to the transmission of Jewish law.
Dei Rossi was also revolutionary in his rediscovery of ancient Jewish writings of the Hellenistic and pagan world—including the first great Jewish philosopher Philo of Alexandria, the histories of Josephus, and the Letter of Aristeas that described the first translations of the Torah into Greek. In many cases, these texts went unrecognized by Jews and had worked their way into the cherished canon of the Church. It is impossible to think of the modern writing of the history of the Jews without acknowledging this pioneer of Mantua. He should be recognized alone for concluding that the Jewish calendar that dated the years from creation was the product of the epoch of the Talmud, not from the Torah received by Moses at Sinai. Azariah dei Rossi was far ahead of his time. Perhaps Graetz, Dubnow, Baer and Baron could have written their classic works of Jewish history without the groundbreaking work of the great Jewish scholar of the Renaissance. But Azariah dei Rossi surely paved the way for the critical study of the Jewish past, a study that has enriched our understanding of thousands of years of Jewish history and have, indeed, opened the eyes of anyone who wants to understand the Jewish people, Jewish culture and Judaism.