La nascita da una Vergine. Perché?
But is there any a priori reason for supposing that, if God was to become incarnate, he would choose to do so by means of a ‘virgin birth’?
It would mean that Jesus came into existence as a human on earth partly by the normal process by which all humans come into existence, and partly as a result of a quite abnormal process. It would thus be a historical event symbolizing the doctrine of the Incarnation, that Jesus is partly of human origin and so has a human nature, and partly of divine origin and so has a divine nature.
This event would help those who learnt about it later to understand the doctrine of the Incarnation.
That God should bring about a historical event which symbolized what was happening at a deeper level seems to me to have a fairly low but not totally insignificant degree of prior probability.