This is an argument against the objection that God, if Christ is His Son, must have suffered loss. If God is His Father and the sole source of His existence, Christ must have come into being by separation from the Father; i.e. the Father must have suffered diminution and lost His completeness. The answer is that a woman—and a fortiori the Virgin, who was the only human parent Christ—suffers no loss of bodily completeness through becoming a mother. There is no allusion to the belief in the perpetual virginity of the Mother of our Lord.