We can, as Catholics, agree it is wrong, and at least evil on the level of distrust in the written word of God, as understood by the Church over centuries and at the Council of Trent.

But is there any evil in it beyond that? Yes.

While C. S. Lewis unfortunately part time embraced this error, like while writing The Problem of Pain, and while this may have been part of his reason not to convert to the true Church which at this time was soundly condemning this error (the book was published 1940, in 1950 Pope Pius XII, if still pope at this point, at least condemned polygenism:

37. When, however, there is question of another conjectural opinion, namely polygenism, the children of the Church by no means enjoy such liberty. For the faithful cannot embrace that opinion which maintains that either after Adam there existed on this earth true men who did not take their origin through natural generation from him as from the first parent of all, or that Adam represents a certain number of first parents. Now it is in no way apparent how such an opinion can be reconciled with that which the sources of revealed truth and the documents of the Teaching Authority of the Church propose with regard to original sin, which proceeds from a sin actually committed by an individual Adam and which, through generation, is passed on to all and is in everyone as his own.

https://www.vatican.va/content/pius-xii/en/encyclicals/documents/hf_p-xii_enc_12081950_humani-generis.html

... while this is so, in other writings, he has actually provided an antidote. He has more than once reminded that while historically, empires may seem more perennial than individual people, seen from eternity the opposite is true : people will inherit Heaven or, if not, go to the fire first prepared for the Devil and his angels. And will enjoy or endure this eternally. Empires are over and done by the hour when the dead step up from their graves : dies irae, dies illa, solvet secla in favilla. All collectives except the most sacred are parts of the favilla, the ashes. Indeed, none of them has lasted the whole time from Adam to Doomsday.

There is a corrollary to this truth. Collectives do not have souls. As they do not have souls, they enjoy no free will. Only individual people do. Therefore the first sin had to be the sin of an individual man, not a "collective sin."

If the first sin had been a collective sin, it would not have been an expression of free will. It would have been as evil of God to punish me for a sin committed by my sixteen great-great-grandparents together that none committed individually, as it would have been to punish me for my daddy spraining his leg.

There is a name for the idea that the fall of man did not follow from a free decision of Adam. It's called Supralapsarian Calvinism. Any Calvinism, including Infralapsarians, claims we are born with no free will at all, at least as pertaining to our salvation, and if we are not predestined by God without our actual decision to be damned, then we are predestined by God without our actual decision to be saved. But Infralapsarians at least claim this state of affairs only came about by the sin of Adam. Supralapsarians claim, Adam's sin was also predestined.

The idea of a collective fall, as it denies freewill in the first human entity to fall, is a modern version of Supralapsarian Calvinism.

Let us recall. The council of Frankfurt, I think it was, stated "Deus neminem predestinat ad malum" - God predestines no one to evil. "Neminem" is singular, so it can readily be translated as no one to evil. God certainly sometimes targets collectives for destruction. But that is due to non-predestined, free-willed, sins of individual people.

But it is not just collectives, but also individuals, that suffer from the sin that is called original. Including individuals who have committed no individual sin themselves, like children born with spina bifida and dying soon. Hence, it is a horrendous blasphemy against the justice of God to claim that this is due to a non-freewilled, either predestined or "predestined by negligence" sin of a collective.

Hans Georg Lundahl
Paris
St. Peter in Chains, Dedicace
1.VIII.2023

Romae, in Exquiliis, Dedicatio sancti Petri Apostoli ad Vincula.