In Conceiving Israel, Gwynn Kessler examines the peculiar fascination of the rabbis of late antiquity with fetuses—their generation, development, nurturance, and even prenatal study habits—as expressed in narrative texts preserved in the Palestinian Talmud and those portions of the Babylonian Talmud attributed to Palestinian sages. For Kessler, this rabbinic speculation on the fetus served to articulate new understandings of Jewishness, gender, and God. Drawing on biblical, Christian, and Greco-Roman traditions, she argues, the rabbis developed views distinctive to late ancient Judaism.

Kessler shows how the rabbis of the third through sixth centuries turned to non-Jewish writings on embryology and procreation to explicate the biblical insistence on the primacy of God's role in procreation at the expense of the biological parents (and of the mother in particular). She examines rabbinic views regarding God's care of the fetus, as well as God's part in determining fetal sex. Turning to the fetus as a site for the construction of Jewish identity, she explicates the rabbis' reading of "famous fetuses," or biblical heroes-to-be. If, as they argue, these males were born already circumcised, Jewishness and the covenantal relation of Israel to its God begin in the womb, and the womb becomes the site of the ongoing reenactment of divine creation, exodus, and deliverance. Rabbinic Jewish identity is thus vividly internalized by an emphasis on the prenatal inscription of Jewishness; it is not, and can never be, merely a matter of external practice.