The idea of Jesus’ pre-existence was developed circa 30-50 CE, and it did not necessarily differentiate believers in him from other Jews. The idea of his virgin birth was developed circa 70-90 CE as a defense against reports of Mary’s early pregnancy. Parthenogenesis was itself novel within Second Temple and early Judaism, and its harmonization with the previously developed idea of Jesus’ pre-existence differentiated proto-orthodox Christians from Jews. It also differentiated them from other Christian groups. Historical-critical methods cannot get at the details of this harmonizing thought process.

Blending theory explains how the two separate ideas of Jesus’ pre-existence and virgin birth were harmonized and how the doctrine of Incarnation through parthenogenesis emerged: blended spaces have emergent structure and meaning that are not reducible to input spaces. Incarnation through parthenogenesis is not reducible to the ideas of Jesus’ pre-existence and virgin birth, any more than it is reducible to Paul and John, Matthew and Luke, Jewish or pagan literature. It was a new idea that emerged from the blending of two separate ideas in the second century and has since been taken for granted as it became proto-orthodox and then orthodox Christian doctrine.

Furthermore the cognitive theory of minimal counterintuitiveness suggests why the doctrine was historically successful: concepts that violate one or two expectations, such as the concept of a pre-existent Jesus who is incarnated through virgin birth, have mnemonic advantage over other concepts that violate no expectations or too many of them.