Polygenism is the view that different races of humans evolved independently of one another, and it directly contradicts the literal interpretation of the creation of Adam and Eve in Genesis. Monogenism is the doctrine that modern humans arose from a single pair of ancestors, but it has no scientific support. So, which is it? Science or theology?
“In no way apparent"
Pope Pius XII addressed polygenism in the 1950 encyclical Humani Generis. He said that it was “in no way apparent" how to reconcile polygenism with divine revelation. Here is the full quote:
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 (37).
Pope Pius XII also wrote that the question of the “origin of the human body from pre-existing and living matter" is open to careful research by scientists and theologians, as long as the dogmatic truths of the Catholic faith are upheld. What are these dogmatic truths?
De fide doctrine
According to Heinrich Denzinger’s Compendium of Creeds, Definitions, and Declarations on Matters of Faith and Morals, a doctrine is “of divine faith" (de fide divina) if it is explicitly found in revelation (8). In Fundamentals of Catholic Dogma, Ludwig Ott names this doctrine as the only de fide doctrine in the section on the origin of the first human pair and the unity of the human race: “The First Man was created by God" (94). Catholics also maintain the unity of the whole human race. This is not a de fide dogma, but a necessary presupposition of the doctrine of original sin and redemption (96).
Then came genetics
Pope Pius XII certainly argued against polygenism, but Humani Generis was issued three years before James Watson and Francis Crick reported the helical structure of DNA in 1953. The understanding of the role genetics plays in evolution was only starting to develop. Darwinian evolution has been reinterpreted in terms of molecular genetics, and now the biological mechanism of evolution is better understood.
Remarkably, there are three scientific observations about human life unique among all other organisms:
- There was a relatively small first population of humans.
- All present-day humans belong to one species.
- We have spread throughout the earth.
More precise terms to come?
Pope Pius XII seems to have left the question open for further development, however subtly. Documents issued after Humani Generis address evolution but make no mention of monogenism or polygenism.
The absence of the terms polygenism and monogenism in theological documents over the last fifty years suggests that theological developments have moved away from them. Perhaps they will be replaced with more precise terminology.
We do not know
We do not have an answer to the question of polygenism at this moment in history, but that shouldn’t disturb our faith. As I explain in my book, Particles of Faith: A Catholic Guide to Navigating Science (and elsewhere), there is a way to make sense of the question. It is not actually an argument so much as a statement of fact: evolutionary science cannot rule out a miraculous monogenetic origin of the human race. I do not say this to make a positive assertion that we know a miracle occurred, only to point out that miracles are possible and not the object of the scientific method.
Nor do I offer a reminder of miracles as speculative theology. I say this for all the parents and educators who must provide answers to Catholic children. Our children grow up being taught about Adam and Eve, only to take a biology class in school and be told about dinosaurs and Neanderthals. We need to be prepared to answer them because they are this moment in history.
The bottom line is this: We do not know. That is all the more reason to learn about the discoveries of evolutionary biologists, geneticists, and anthropologists so that we can better understand what it means to be human. We should not teach our children that one must choose between science or theology, for that contradicts a most fundament truth of faith, that truth cannot contradict truth.
Submit to the judgment of the Church
The Magisterium safeguards the truths of faith. Pending any declarations from the Magisterium on the matter, we must continue to do as Pope Pius XII taught—to “submit to the judgment of the Church, to whom Christ has given the mission of interpreting authentically the Sacred Scriptures and of defending the dogmas of faith" (Humani Generis, 36). That is how to explore the topic of human origins, and think with the Church.