The Roman emperor Antoninus had a private and unusual friendship with Rabbi Judah ha-Nasi, the compiler of the Mishnah (the earliest code of rabbinic law). They met in secret and debated theology, philosophy, and the nature of the human soul. One of their most famous exchanges concerned the origin of evil.
Antoninus posed the question directly: "At what point does the evil inclination — the yetzer ha-ra (the evil inclination) — take hold of a person? From the moment the embryo is formed in the womb, or from the moment of birth?"
Rabbi Judah initially answered that the evil inclination enters at conception — from the very first moment of formation. Antoninus objected. "If that were true," he argued, "the fetus would kick its way out of the womb and rebel against its mother. The evil inclination cannot be present before birth, because we see that the unborn child is peaceful."
Rabbi Judah reconsidered — a remarkable moment, since he rarely yielded to anyone. He examined the scriptures and found support in (Genesis 4:7): "Sin crouches at the door" — meaning at the door of birth, not the door of conception. The evil inclination waits. It enters at the moment a person emerges into the world and takes their first breath.
The Talmud in Sanhedrin (91b) and Genesis Rabbah (34:10) preserve this as one of the rare occasions when a Roman ruler corrected a Jewish sage — and the sage had the integrity to accept the correction. Antoninus understood something about human nature that even Rabbi Judah had not fully grasped: that evil is not innate. It arrives. And if it arrives, it can also be resisted.