In the same encyclical in which Pope Pius XII allowed Catholics to believe in evolution, he seems to have proscribed belief in polygenism with these words:
When there is a question of another conjectural opinion, namely, of polygenism so-called, then the sons of the Church in no way enjoy such freedom.
For the faithful in Christ cannot accept this view, which holds that either after Adam there existed men on this earth, who did not receive their origin by natural generation from him, the first parent of all; or that Adam signifies some kind of multitude of first parents; for it is by no means apparent how such an opinion can be reconciled with what the sources of revealed truth and the acts of the magisterium of the Church teaches about original sin, which proceeds from a sin truly committed by one Adam, and which is transmitted to all by generation, and exists in each one as his own.
Pope Pius XII seems to have hedged the definitiveness of his declaration against polygenism by stating, “it is in no way apparent how such an opinion [polygenism] can be reconciled with that which the sources of revealed truth….”
Does this mean that if polygenism can be reconciled with the sources of revealed truth about original sin, then polygenism would be doctrinally acceptable?
Though there is debate on this issue, theologians today believe that Pope Pius XII left the door open to this possibility if the condition in his declaration could be met.
Whatever the case, Monogenism is compatible with the evolutionary picture of the emergence of Homo sapiens sapiens (and Mitochondrial Eve). Why?
Because the emergence of our first parents is not necessarily connected to either Mitochondrial Eve, Y chromosome Adam, or both. They emerged when God infused the first transphysical soul into the first Homo sapiens (not necessarily Homo sapiens sapiens). This first couple committed the original sin which caused the fall of the rest of humanity. The emergence of the rest of humanity comes from these first parents.
If Mitochondrial Eve is not the first mother, then she is in direct lineage from our first parents—and if Y chromosome Adam is not our first father, then he is in direct lineage from them as well. The progeny of our first parents were also given unique transphysical souls by God, but their nature was weakened by the sin of their first parents.
As a result, they lost their exemption from death and felt the effects of concupiscence because the presence of God to their souls was weakened, making them more easily tempted and deceived by their sensual passions and the evil spirit.
Though these effects are present today, they are mitigated by the redemptive act of Jesus, the presence of His Church, and the presence of the Holy Spirit.
This brings III.B to a close. Next week we’ll discuss whether there was suffering or death before the fall.