Rabbi Yehuda HaNasi — the editor of the Mishnah — conducted long conversations with the Roman emperor Antoninus. Their friendship is one of the warmest cross-cultural exchanges in rabbinic literature. Antoninus was not a convert, but he took Jewish thought seriously, and the rabbi took Antoninus's Stoic instincts seriously too.
Gaster's Exempla (1924), No. 270, preserves one exchange with particular weight. The question was: when does the yetzer hara — the evil inclination — enter a person? And when does the neshamah, the soul itself, arrive?
Rabbi Yehuda, in an exchange recorded more fully in Sanhedrin 91b, reports what he learned from Antoninus. "The evil inclination," the emperor argued, "enters a person at the moment of birth, not before. A fetus in the womb has no capacity yet to will harm. The inclination is born with the child."
And the soul? Antoninus answered: "from the moment of conception." The neshamah is there from the very first union. The body is alive with spirit long before it is alive with temptation.
Rabbi Yehuda took the argument as sound and attributed both insights to the emperor. It is a remarkable act of intellectual generosity — the greatest Jewish legal authority of his age conceding that a Roman had clarified a question about the inner architecture of human life. The soul, it turns out, arrives early. The struggle with it does not begin until the first breath.